Admittedly, this may be more of an observation than hint. On most full screen apps I use (Reeder for Mac, Mail, the fugly iCal) you don't typically need another window.
I have always had Safari to open new windows as tabs. I think this may now be the default in full screen mode. If you want another full screen invocation of Safari, just hit Command+N.
By extension: each Safari window with its own set of tabs can independently be in full screen mode or not.
[crarko adds: This doesn't actually run a second copy of Safari, it just creates a new Space and puts the new full screen window in it. It looks like Preview does something similar when you open multiple documents while running full screen.]
You can take screenshots with keyboard shortcuts, the Grab application, or third-party applications. The Lion version of Preview takes screenshots now, too.
In Preview, select File » Take Screenshot, and select from the three options: From Selection; From Window; or From Entire Screen.
When you select your menu item, an overlay appears reminding you what to do next. You can use the Application Switcher (Cmd+Tab), Mission Control, or left-right trackpad swiping to get to the desired desktop and application. Then select the desired screen area or window and click to take your screenshot. You can't take a screenshot of menus this way because you have to click to bring up a menu. (For that, select the desired menu/submenu and use the good, old Cmd+Shift+4 » Space bar keyboard shortcut.)
OK, so why go to all this trouble when I can just use Cmd+Shift+3 or Cmd+Shift+4 to do the exact same thing with a lot less trouble? Well, frankly, most of the time you wouldn't. But Preview has some nifty tricks up its sleeve that it's inherited from the venerable Grab application.
Selecting the From Entire Screen option gives you a 10 second countdown so you can get things just the way you want, which with Mission Control and Spaces is easier than ever because you can setup one desktop for your screenshot and open Preview in another. You have time to position the cursor where you want it, too.
After you take the screenshot, instead of dropping a new file on to your desktop, the new image opens right up in Preview where you can edit it as desired, including cropping out undesired parts and adding annotations. Click the Close button (or the Save... or Export... menu item) and you can choose from one of six different image formats, including JPEG, PDF, or even OpenEXR. You can name it and save it wherever you want, and there's Versions and Full Screen support, too. (Full screen screenshot pranks, anyone?)
Longtime users of Grab will likely say, 'So what?; But Preview has incorporated Grab's features and brought them nicely forward with support for the latest APIs and UI features. You've heard of Grab, right?
A little history: A hold over from NeXSTEP/OpenStep, Grab is an odd little app that's been around since the very first version of Mac OS X. Grap.app lives on in Lion; version 1.6 (build 109) copyright 1995-2011 is in your Utilities folder.
[crarko adds: Grab was always one of those programs I saw people having difficulty understanding how to use. It was kind of a strange process, not unlike taking a screenshot in Windows. This way seems to be far more intuitive.
*Changed from a 10.7-only hint as people have noted this is also present in earlier versions.*]
There was once a hint that worked for previous versions of Mail about three-fingered scrolling to flip through messages.
With Lion, the three-fingered flip now launches Mission Control, so navigating through Mail messages has changed to a FOUR-fingered flip. It took me a while to figure it out on the Magic Trackpad -- it seems to call for a little practice.
A flip Up/Left brings you to the next message up the list; a flip Down/Right brings you to the next message down.
[crarko adds: This is starting to take on the feel of learning to play a new musical instrument, which is not all bad, and possibly intentional on Apple's part.]
Mail's 'Include related messages' preference shows sent messages together with received in the preview pane, however it fails to show them in the message list. It also doesn't send them to the trash when deleting a thread.
I replaced Inbox in my favorites bar in Mail with Conversations, which is a smart mailbox containing all messages that are in Inbox or in Sent. Now, not only do I see related messages on the right, if I open a thread on the left, they're all there, too. Plus, when I'm done with a thread and I choose to delete it, all the related messages also get deleted, instead of sticking around in my Sent mailbox.
It's not immediately obvious that more options exist due to the new scroll bar display.
Open Dictionary (it lives in /Applications in case you didn't know) and select Dictionary » Preferences. Scroll down the list of options and enable the two British options. Then click on them and drag them to the top so they take precedence.
You can leave the two existing American options enabled for the odd occasions that they might be useful. This tip pre-supposes, naturally, that British English is a better choice for you than the US dialect.
The other options previously available in Snow Leopard appear to remain largely unchanged. (The New Oxford American Dictionary has been upgraded from the 2nd edition to 3rd.)
[crarko adds: Nice to have the new options for our friends across the Pond.]
10.7 adds a Quick Look option to Mail for viewing webpage URLs in emails.
In Mail, just right-click (Control+click) a link in an email and select
'Quick Look URL' from the contextual menu.
[crarko adds: When I tried this the Data Detectors in Mail identified some URLs and gave me this option. Curiously, with others right-clicking on them just opened the link in Safari. I'm not sure how it made the distinction. Also, the time it took for the Quick Look preview to appear was pretty long. It's probably just as effective to open the link in a browser. Nevertheless, it is a feature to document, so here it is.]
A previous hint described how to extract images from Keynote by opening the file package. The latest iWork versions use compressed packages which add another step to that process.
A simpler alternative is using the inspector palette within the program.
To extract the original image from an iWork application:
Select the image you want.
Open the inspector palette and select the Metrics tab. (The one with the ruler.)
The first item 'File info' shows a file icon and name.
Drag that icon to Finder and you have your original image.
Credit goes to Peter Bries in the Apple Discussion Forums for reporting this.
[crarko adds: I tried it, and it worked in Pages.]
Snow Leopard had introduced a very cool function in mail where you could scroll through messages by swiping three fingers up or down. Unfortunately this function broke in Lion.
After a lot of trial and error testing, I found the same function has now been remapped to swiping three fingers left or right. Don't know why this changed, but am happy that I do not have to shift between the trackpad and keyboard to read my mails.
Also pressing 'Space' takes you to the next message.
[crarko adds: What I found is that pressing the Spacebar will scroll down by pages in the current message, and then when the end is reached progress on to the next message.]
Upon opening Logic Express 9 for the first time after upgrading to Lion, I received a notification that some of my audio units were unavailable (one of these unavailable audio units was AmpliTube 3, which I use for all of my guitar tones!). Fortunately, the fix was very simple: I opened Logic Express in 32-bit mode, and when I returned to 64-bit mode, the previously unavailable audio units were functional again.
Here are the steps I took:
Close Logic Express.
Navigate to the Applications folder and open the info window for Logic; select its icon, and Control+click Get Info, or press Command+I.
In the Info window, click the box for 'open in 32-bit mode.'
Open Logic Express, allow it to scan the audio units and finish loading, then close it.
Open the Info window again and uncheck 'open in 32-bit mode' to return to 64-bit mode
All 32-bit audio units should now be available in 64-bit mode.
[crarko adds: I haven't tested this one, but it sounds about right.]