Jeff Veen actually found a great use for his Treo.
I remember running the LA marathon a few years ago and trying to keep track of the same data myself. As my pace slowed over the long distance, I occupied the time by constantly calculating my minutes/mile in my head, according to my wristwatch time. If there was a way to keep a constant readout on your watch, based on input from the race course markers, you might have a killer app for runners. A steady pace is sometimes hard to keep up, especially when you're running alone.