That's pretty cool.
I've been working with the dev on another similar app called gMeter. It's a windows mobile app, specifically designed for the HTC Touch Pro (ATT Fuze), Touch HD, and Touch Diamond.
http://www.extreme-apps.com/scrsht.php
It has a lot of the same functionality (plus or minus), uses the accelerometer and the GPS simultaneously, and does have Excel file output support (csv), as well as on screen lap displays with accel and decell points. Pretty cool.
I want to take it with me to the strip, like you did, to see just how accurate it is...