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: This scans the system log file for the last three entries from backupd, displaying them on the desktop. Use whatever refresh value you'd like; 10 minutes is good enough for me.
I'm also able to monitor remote Time Machine activity from other computers backing up to a local disk connected to my computer. Just use this command in GeekTool: If you've set up passwordless ssh login, you're golden.
[robg adds: I haven't tested this one.]

