Growl - a global notification system for Mac OS X
Always nice to find out that there is always one application, that was unknown before and becomes a must-have for an alpha-geek.
Growl is a small utility that adds nice notification messages to your system. Something like Synergy is for iTunes but for the whole system. Lots of applications can use Growl.
It notifies you when your downloads from safari have finished, when new mail is there, shows what iTunes is playing. Very surprising when an app you’ve used before shows Growl-Messages. For example Ecto, my weblog-editing tool.
Check out Grow, get a free download from http://growl.info/files/Growl-0.7.dmg (.dmg-file, 2 MB).