I've been having some problems getting Time Machine to work properly, and I've grown tired of opening the Time Machine System Preferences pane just to see if Time Machine executed when it was supposed to. Using GeekTool -- which runs well on Leopard -- I'm now able to get a regular status report effortlessly, which has eased my mind considerably since I now know Time Machine is working properly.
Create a new shell entry in GeekTool, and enter the following command:
Mac OS X Hints
http://hints.macworld.com/article.php?story=20071211214606753