I spent most of today writing another useful utility, TrayTimer. It adds a tray icon that you can click to set timers, much like a kitchen timer. Here's a screenshot:
When you click on the tray icon, that window pops up, much like when you click on the clock in Windows Vista. You can then add timers using the text fields on the right. The timers that you've added show up to the left. You can click on the button that shows the time remaining to pause the timer. When a counting-down timer reaches 0, a window opens up that says "Timer 1: Time's up".
The code for the program is available at http://jwutils.googlecode.com/svn/trunk/projects/text/binutils/src/com/googlecode/jwutils/timer/. Download all four source code files, compile them, and run TrayTimer. Or you can svn export that url and compile it. I'll post a download soon that contains the whole thing already compiled.