Unfortunately Apple decided to drop support for PPC, SDKs 10.4/10.5 and GCC 4.0 in Xcode4. This hasn't been done for technical reasons, though, but only because Apple wanted to do that. If you have a parallel installation of Xcode3 on your Mac, you can easily restore all that functionality to Xcode4. I posted a detailed step by step guide at Stack Overflow how this can be done. For convenience and to reach a wider audience I'm posting it here again.

Before I get to the how it is done part, here are some notes about my patch/hack/fix. Right from the start the major goals have been:

• Keep all modifications to an absolute minimum.
  We want to keep the Xcode setups as original as possible.
• By all means, try to avoid patching or modifying any files.
  We want all files to stay untouched and keep their original content.
• Try to avoid moving or copying files around, unless absolutely necessary.

I was able to keep all those goals. Almost everything is done by creating symlinks. Only a single existing symlink had to be replaced and we'll back it up before replacement, just in case.

If you are no expert on terminal operations, I strongly advise you to copy/paste all terminal commands from my reply to your terminal, to avoid typos. Bear in mind that even spacing, quoting and especially capitalization can be important. Copy/paste them line by line, never more than one line at once and hit return after each pasted line to execute the command. Should any operation ever prompt you for a password, this will be the password of the currently logged in administrator user (your keystrokes are not displayed while typing, this is normal, don't worry, just keep typing the password and hit return; re-try if you had a typo and get prompted again).

If you have multiple FaceTime devices: iPhone, iPad, iPod Touch, Mac, Multiple Macs, etc. The iPhone's ID is the phone number, but the rest use an e-mail address. If you don't want them all to ring when someone is trying to contact you, then they each need a different address. You could set up a separate e-mail address for each device, but that's a pain.

All you need to do to have multiple IDs per e-mail address is append '+something' to the e-mail address. For example if your e-mail address is jon@example.com and you wanted to have a separate FaceTime address for your iPad and for your Mac you could use: jon+mac@example.com and jon+ipad@example.com.

As an aside, e-mails sent to jon+mac@example.com and jon+ipad@example.com will still go to jon@example.com as well. In general adding '+something' to your e-mail is a useful way to keep track of who is sending you mail (provided the services support it).

[crarko adds: I haven't tested this one, yet. As soon as I get an iPad 2 I will revisit this, though.]

Using information found in the article listed in the Comprehensive summary of Mac Metadata hint, I was able to find a way to write metadata from the CLI, making it possible for shell scripts to modify files in a way that is visible to the Finder, and therefor in Smart Folders and other search results.

Using xattr on the CLI you can write arbitrary metadata to files. This is useful for other CLI scripts because you can search for these arbitrary attributes using mdls. However, if you want to set metadata that is easily searchable in applications like Finder, you have to set the values for existing attributes.

I use a lot of Groups in Address Book and sometimes a Group member's contact info has more than one e-mail address listed in AB. It annoyed me that sending e-mail to a Group often resulted in the 'wrong' address being used, i.e. the contact's private one instead of work.

It turns out that you can choose which address you wish to be used for Group contacts by right-clicking on the Group in Address Book and selecting 'Edit Distribution List.'

You'll get a listing view where you can set the default information for each of the recipients.

Maybe not the greatest hint ever, but hopefully useful for someone.

[crarko adds: I tested this, and it works as described. This previous hint took the approach of creating different Groups for the various e-mail address types if you want to distinguish them. It depends on how you use Groups.]

This is an update to an old 2008 hint for Leopard. Basically the hint explained how to have an icon in the Dock for Help Viewer and how to set its windows to non-floating mode. Of course it didn't work anymore in Snow Leopard, since some of the terminology changed.

To activate Help Viewer DevMode type this in a terminal window:

defaults write com.apple.helpviewer DevMode -bool true

and to deactivate it type this:

defaults delete com.apple.helpviewer DevMode

In DevMode Help Viewer has an icon in the Dock and its windows are non-floating windows. Note that the original hint modified a key in the app's Info.plist for the icon in the Dock part of the hint which would break Help Viewer's code signing on Snow Leopard.

[crarko adds: I tested this, and it works as described.]

This is a tip about flagging entries in a .bib file using BibDesk.

I wanted to have entries which I printed from my bibliographic data base flagged. That is, being able to know if I already have a hard copy of an article for example.

In BibDesk preferences » Fields I added a boolean field called 'Printed.' Then I created a smart folder which contains all the entries with this flag true.

The non-computerized part is having a physical folder where I store alphabetically all the articles I printed. This way I can easily find papers without re-printing them.

[crarko adds: I haven't tested this one. I admit I had never heard of BibDesk before, so if others have need to manage a bibliography and haven't tried it, here is something new for you, too.]

Here's an easy method to remove email based on the IP address of the sender in Mail.app.

Every time I receive a spam email I add its email address to a list of rules in Mail to move it directly to trash. The length of this list has grown over time and I now have more than one ever-growing list. After a while I noticed that, although the sender addresses were different, the IP address in a lot of cases stayed the same. I looked at the rules in the Mail prefs, but there is no obvious rule for filtering by IP address.

However, it can be achieved using the rules, with a little tweak.

Firstly, it might be a good idea to create a new Mailbox and call it something like 'Review Spam.'

Next, identify the sender's IP address from the spam messages. If you don't know how to do this, here's a rough guide:

Select a spam message and select View » Message » Long Headers -- the header section in the message will expand. In the header you should see several 'Received' headings with aome text next to them and an IP address.

The text and IP in the first 'Received' heading is likely your own Mail server -- you don't want to add this to the rule otherwise the rule will act on all your incoming mail from that server. This can be a bit tricky if you don't know what you're looking for, but if you analyse the spam messages against legitimate messages you should be able to find the offending IP address, eventually.

To create the rule that does the filtering:

• Select the 'Rules' tab in the preferences for the Mail.app.
• Create a new rule by clicking 'Add Rule.'
• Make sure 'Any' is selected in the conditions list, then in the 'Recipient' list, scroll down and select 'Edit Header List.'In the resulting window, click the button with the + symbol to create a new list item and type 'Received' in the field.
• Close the window and select the 'Recipient' list again; you should see a new item near the top of the list called 'Received.'
• Select that item and make sure 'Contains' is selected the corresponding list. Enter the sender's IP address into the text field next to the 'Contains' list.
• In the actions section, select 'Move Message' and then select the 'Review Spam' mailbox (Or trash, if you're feeling brave and trusting) in the mailbox list.
• Click 'Ok' and then 'Apply.'

[crarko adds: I haven't tested this one. You can check some non-spam messages for the IP address in the header and the one they all have in common should be the address of your mail server for the given account, so you know not to filter it.]

If you want to jump to a specific date in iCal using keyboard shortcuts, you'll need to add the 'fn' key to your arsenal.

If you select Go to Date... from iCal's View menu, you may have noticed the the typical OS X keyboard shortcuts do not seem to work. Pressing 'esc' does not activate the Cancel button, and pressing 'return' does not activate the Show button (despite it having the throbbing blue default appearance).

But using the 'fn' key and and then pressing 'return' will activate the default Show button.

Note: Even on a keyboard with a separate 'enter' key (which is what fn-return is supposed to activate) hitting simply 'enter' will not activate the button. The 'fn' key is required there also.

[crarko adds: I tested this on a MacBook, and it works as described. I also found that Ctrl+Enter Ctrl+Escape worked on a desktop Mac with a keyboard that didn't have a 'fn' key. Other combinations may work as well. The thing to take away here is that the behavior of this shortcut in iCal is quite inconsistent with the standard interface, for no apparent reason.]

For some strange reason, the page up and page down buttons on my keyboard never cooperated with Pages. What I wanted to be able to do was to simply hit those keys on the keyboard, and have Pages scroll up or down to the next page.

You'd think it would do that, but it doesn't. It would always scroll a little more or a little less than a page. Quite maddening. There is a little blue scroll triangle at the bottom of the page that can be clicked to do that, but I wanted to do it with the keyboard.

The macro editor QuicKeys was my solution. I was able to write a simple macro to click that button, and assign the action to the key.

The details:

• Create a new shortcut in QuicKeys.
• The action is to 'press button.' The location of the button is specified by the number of pixels relative to a defined location; in this case, the left lower corner of the Pages window. On my monitor it was 357 pixels horizontal by -7 pixels vertical, for the page down click, and 339 horizontal by -7 for the page up.

[crarko adds: I thought one might be able to assign keys in Pages using System Preferences » Keyboard » Keyboard Shortcuts » Application Shortcuts. To my surprise, Pages (and Keynote and Numbers) did not show up in the list of applications I could choose to assign a keyboard shortcut to. I could add it using 'Other.' Is this because the iWork suite is installed by default into a subfolder in /Applications?]

When confirming wether faces recognized by iPhoto '11 are actually correct, some will be wrong and need to be rejected.

iPhoto gives the hint to 'Click to confirm or Option-click to reject,' yet the easier and faster way to reject would be to simply double click the image, after which it will be marked as 'Not (name).'

[crarko adds: I tested this, and it works as described. Yet another undocumented feature of iPhoto.]