I just heard about this new company that is selling video setup for
recording airplane flight training: http://www.reflight.com/

Wasn't clear from the website, but it looks like either now or in the
future, the recorder will accept NMEA input from a GPS so one could
correlate video with position.

A bit more expensive than something one could cobble up themselves,
but it's a complete package that's specifically aimed at aviation.

-Tom