[Stefan] sent in this data logger that was built for a weather balloon project. It's a very clean design that logs to a 64KB eeprom, can transmit its location via SMS through a cell phone and trigger a camera based on position if needed. The site has a tarball will full schematics and source - mod away.
http://www.hackaday.com/2007/09/11/simple-gps-data-logger/