Every now and the Apple posts a small video tutorial on their website and even for highly skilled Mac-fans there's something to learn. Fx. did you know there is 3 different ways to do screenshots in OS X?

1. screenshot of complete screen
2. screenshot of selected area
3. screenshot of application window, fx. firefox and/safari

Actually quite neat if you need image data for tutorials and/or press material. The shortcuts are as follows:

1. Cmd + shift + 3
2. Cmd + shift + 4
3. Cmd + shift + 4 - space

The command key is also known as the "apple key". Link:  http://www.apple.com/business/videotips/?movie=snapshots