By default, Mail will keep file attachments that you've opened or viewed in your ~/Library/Mail Downloads folder, until you delete the associated email. You can save disk space by making the following switch:
In Mail's preferences, go to General, then set Remove unedited downloads to When Mail Quits. This does not remove the attachment from your email, just from your local cache of Mail Downloads.
On one machine I've got, I reclaimed nearly half a gigabyte after using the system for only a few months! I can't wait to see how much I get back on a system I've been using for 5 years!
[kirkmc adds: I find it odd that Mail keeps these attachments after you view them, since they're still in the emails. This is only an issue, however, if you save emails with attachments; if you delete them, then the default setting deletes the cached files as well.]
Having originally upgraded to 10.8 from 10.7, all of my applications' desktop assignments in (now) Mission Control were already set. I recently decided to wipe and install a fresh copy of OS X 10.8.3, and discovered that, for many of my apps, the option to "Assign to..." particular desktops or to all desktops was missing. After roaming through forum after forum I finally found a workaround for this bug.
Thankfully it's relatively simple. If you right-click on the Dock icon of a running application and you find that the "Assign to..." option is missing from the "Options" sub-menu (and of course you have multiple desktops setup in Mission Control first), if you launch the application from LaunchPad, the option to assign the application to a particular desktop will a) magically appear, and b) continue to use that assigned space regardless of how it is launched in the future.
Hope this is helpful. I spent a few good afternoons trying to fix this. Supposedly there is a bug open in Radar at Apple about this issue since the 10.8 release but it still has yet to be fixed as of 10.8.3.
[kirkmc adds: I use Spaces; um Mission Control, or whatever, and haven't seen this. The only time I have issues is when I update an app via the Mac App Store and launch it. It then doesn't go to the assigned desktop, even though the Dock menu shows that it is, indeed, set to stay on that desktop. But when I move it, it stays there after the next reboot.]
You can set up Facebook chat in Messages. Since Facebook uses Jabber, all you need to know is your user name, and you can create an account.
Open Messages' preferences, and click on Accounts. Click on the + icon to create a new account. For Account Type, choose Jabber. For your account hem, you'll need to find your Facebook user name; this is the text after http://www.facebook.com/. The account name for the Jabber account should therefore be email@example.com. Enter your Facebook password in the Password field, and click on Done.
Messages should log into the account, and you should see a message saying:
You are now Online to Chat | You are now Online to Chat. Please note that this also marks you as Online on facebook.com.
You can check Facebook to confirm this; you should see that you are online for chat when you visit Facebook.
A Stack Exchange user asked a question a while back: is it possible to turn off the swipe gesture in Chrome that goes back or forward a page? If you're not familiar with this gesture - which works in most browsers on OS X - you use a two-finger swipe to the right to go back to the previous page you've viewed, and a swipe in the opposite direction to go forward again. But this use found it got in the way.
Fortunately, another user found a Terminal command that turns this feature off. Run this in Terminal, then relaunch Chrome for it to take effect:
Apparently you can issue this command for other apps, replacing the com.google.Chrome.plist with the appropriate file name. I've only tested this with Chrome, but if you feel like testing with other apps, post in the comments to say which ones work and which don't.
You recently published a hint explaining how to open a new Finder window in the same folder as the frontmost window, using an AppleScript. Here is an easy way to do the same thing: no Applescript, no special apps needed.
In the Finder, make sure the Path Bar is visible (View > Show Path Bar). The current path is then displayed at the bottom of each Finder window.
As with any other folder icon in the Finder, Command-double-clicking on any icon in the Path Bar will open a new window to that folder.
The current folder is always displayed last in the Path Bar (even if the Path Bar is to short to display all the names), so Command-double-clicking on the last icon in the Path Bar will always open a new window to the current folder.
A user at Stack Exchange asked an interesting question recently : how can you open a new Finder window in the same folder as the frontmost window? When you open a new Finder window (Command-N in the Finder), it opens to the folder you've set in the Finder's General preferences. There may be some situations when you want to duplicate the current window, such as when you're moving files around among sub-folders in a specific folder.
Another reader, Lauri Ranta, posted a simple AppleScript, that you can use together with a keyboard shortcut, to do just this. When you run the script, it creates a new window at the same location as the frontmost window. Here's the script:
tell application "Finder"
target of window 1
make new Finder window to result
make new Finder window to home
Save this as a script, and use any tool that can apply keyboard shortcuts to AppleScripts. Or save it as an application, drag it to the Finder window toolbar, and it'll be just a click away. (You can move the application to any location you want afterwards.)
Quick Look uses WebKit to render SVG (scalable vector graphics) flies, and Safari has a bug that mis-renders any isolated horizontal or vertical line segment making it useless. Most SVG graphics programs like Inkscape or Illustrator are very slow to launch. Fortunately Firefox works correctly and opens SVG files instantly. So if you need to view SVG files, you can drag them into a Firefox window, or onto the Firefox icon in the Dock, to view them.
[kirkmc adds: I tried opening some SVG files in both Safari and Firefox, but didn't find any that had isolated horizontal or vertical lines, so I haven't seen how this issues displays. YMMV.]
If you have an iPad or iPhone, and a friend wants to check out a web site, or your child wants to play a game, you may not feel comfortable lending them the device, since they can access your email, bookmarks, contacts and other personal data.
There's a way to lend a device to someone, however, so they can only access the current app. Go to Settings > General > Accessibility, and scroll down to the Learning section and tap Guided Access. Turn this on, and enter a PIN. Go back to the Accessibility settings, and scroll all the way down: you'll see, in the Triple-click section, that Triple-click Home is set to Guided Access. (Unless you've already set something else for the Triple-click Home setting.)
Now, to lend your device to someone, open the app they're going to use, triple click the Home button, then tap on Start. (You can also set some options before allowing access; tap the Options button at the bottom of the screen.) When the user is finished, triple click the Home button again to exit Guided Access; you'll need to enter the PIN.
I can't find a hint for this on the site, and it's probably not new, but I only just stumbled on this. The Finder toolbar, by default, has Previous and Next buttons that let you navigate back and forth in folders. If you click the Previous button, you'll go back, one window at a time, to all the folders you've visited in that Finder window. But if you click and hold that button, you'll see a list of all the folders you've visited, and can jump to any of them by selecting one. This is a good way to get to a folder you've used but that's far from where you are in the file system.
I've just moved from a country where I had unlimited (really) data on my iPhone contract to one where data plans are metered and expensive. So this recent article by David Chartier, on the Finer Things in Tech web site, comes at the right time. It points out the simple setting in iOS to turn off automatic loading of images in Mail. As with Mail on OS X, you can load images later, but you won't need to load them for every message, saving download time and bandwidth.
To change this setting, go to Settings > Mail, Contacts & Calendars, and toggle Load Remote Images to OFF. If you get an email with images, and want to see them, just tap on Load All Images in the message.
This setting would make more sense if it only affected image downloads when using cellular data. But it's an all-or-nothing choice, so even when you connect via Wi-Fi, you'll need to download images manually, if you use this setting.