Leave Growl notifications on screen!
Growl notifications are great and are so well implemented in many applications. There is an option in Growl preferences so that it leaves the notifications on screen when the computer is inactive for more than 30 seconds (you can change the length of time). It works well when you are away from your computer. You'll be able to read everything that happened on your Mac when you come back. The option is in System Preferences, under Growl (if you don't have Growl installed, you can check the previous tip or search Growl on MacUpdate or VersionTracker).