Launchpad uses a blurred version of your Desktop image for its background. Hitting Command+B while in Launchpad cycles through the original image, the blurred one, a black and white version and a blurred black and white version.
[crarko adds: A couple of people mentioned this. I don't necessarily see much use for it, but apparently one of the Launchpad developers thought it was a nice touch.]
Just as you can now drag files from Safari's downloads list, you can also drag them from a stack. They can be dragged to the Desktop, Trash, Finder window, folder, folders and volumes in the Sidebar and Toolbar and even another Stack.
Also, while Lion unfortunately does not allow quick access to the Desktop with hot corners this can be somewhat remedied by creating a Desktop Stack to do so without leaving the application. It doesn't work in List View so it helps to set it to sort by date added.
This is also very handy for dragging images and items in the downloads menu from a fullscreen app like Safari to the Desktop. The Dock even automatically pops up if you drag the item to the bottom of the screen without having to use the double down motion normally required to access the Dock in fullscreen apps.
[crarko adds: A good trick to know if you use fullscreen apps a lot.]
MacOS X Lion introduces a new Finder Toolbar icon: Label. The toolbar item consists of a drop down menu allowing you to color/label whatever you have selected. But you don't have to use it as a drop down -- just hit the icon and whatever is selected will immediately be colored with the color shown.
You can change the color of the immediate button-press option by choosing the color (or 'No Label') with nothing selected.
[crarko adds: Nice find, and a good new addition to the Toolbar items.]
The new 3-finger trackpad gesture in Lion is used to drag stuff - like moving and resizing windows, selecting text, etc.
I don't know if it's intentional or as a side effect of other gestures, but if you start dragging a window then release just one or two fingers, but not all three, then the drag will stop, but it has some inertia applied to it, much like 'normal' scrolling.
My colleague invented a new game called Window Pong -- can you throw a window from one side of your desktop to the other?
[crarko adds: OK, what I found when I tried this with the Magic Trackpad was after I started dragging a window with the three-finger drag and then let up to go to two fingers only, I could keep dragging the window indefinitely. Then if I let up again to only have one finger, it would still keep on dragging. When I went from three fingers directly to one the drag action stopped right away. I think this may have to do with the sensitivity calibration of the hardware. I'm also running 10.7.1, so the behavior may have changed if the submitter was running 10.7 at the time.]
Want to make your Launchpad folders look a little more distinctive? Use another new Lion feature -- Emoji! See this example picture.
To add Emoji to your folder titles, first open a text box in any normal application and go to the Edit menu and select 'Special Characters.'
In the window that pops up, go to Emoji and pick out the characters you want. Double click to add them to the text box you're in, then copy them to the pasteboard by selecting them and pressing Command+C. Finally, open Launchpad, open the folder you're interested in, click on the title text, and press Command+V to paste it in. Et voilą, you've got a spiffy looking Launchpad!
This tip can also be used for iOS once you've turn on Emoji support there.
[crarko adds: This is more of an Easter egg than a hint. Still, it's good to note the existence of the new character symbols. It's too bad there's not a Dogcow in there.]
In Leopard and Snow Leopard, you could move all of an application's windows from one space to another by holding the Shift key. This no longer works in Lion's Mission Control.
But the windows of an application are grouped together and badged by the application's icon. It turns out this icon behaves as a handle for the windows underneath it -- you can drag it to another space, and it pulls all its windows with it.
It's worth noting that this applies only to the icons that sit on the windows themselves, not the Dock icons.
[crarko adds: I tested this, and it works as described.]
Lion allows you to set a different desktop picture in each space.
All you need to do is open System Preferences in the first space whose desktop you want to change, open Desktop & Screen Saver, and select a picture.
Then enter Mission Control, drag System Preferences to another space, and go to it. Change the desktop picture here, and you'll find it only affects the current space. And these changes are maintained between restarts, even if you choose not to 'Reopen windows when logging back in.'
Simple and somewhat intuitive, yes, but not necessarily obvious.
[crarko adds: That's actually pretty slick, and useful.]
Here's is a very simple tip for working with .webloc and .textClipping files. Sometimes I drag some selected text to the desktop to create a clipping that I can forget about until later. When the selected text is an actual URL, the clipping becomes a .webloc file instead of a .textClipping file, of course.
I find that I want to quickly get either the contained URL of the .webloc file or the contents of the .textClipping back onto the Clipboard in a hurry. One quick way to do that is the same way I would get the text path of a normal file to my Clipboard. I just begin dragging the .webloc or .textClipping file to the upper right corner of the screen, and sometime before it gets there, I press Command+Spacebar to activate the Spotlight search field.
When I drag the file into the search field, I drop it in there while the cursor displays a green circle with a white plus sign. If it's a .webloc or a .textClipping, the search field instantly displays its contents, which is already entirely selected in the field.
I could press Command+C to copy the text, but because I'm not actually searching, I usually press Command+X to cut the text and leave the Spotlight search field empty and ready for its next use.
[crarko adds: I tested this, and it works as described. You might have to go into System Preferences » Keyboard » Keyboard Shortcuts » Spotlight and turn on the Command+Spacebar shortcut.]
It seems that older photos retain their tiny, pixelated, thumbnails. They are not very helpful in Cover Flow view.
Here is the easy way to improve this:
Choose cover flow view so that you can pick out the low resolution thumbs. Order the list by date, putting the older, pixelated ones at the bottom. Select only the pixelated images. (This trick will not work if any of the files have a higher resolution thumbnail. I'm not sure why.)
Choose Inspector (Command+Option+I) and select the multiple thumbnail icon in the upper left hand corner, just left of the number of items.
Press Delete. All the thumbnails will now be regenerated at normal resolution.
It's possible this hint has been posted earlier. I did a quick search and didn't see anything.
[crarko adds: I did a quick search and didn't find anything either. I didn't have any of the low resolution thumbnails on the images on my MacBook to try this.]