Hey Scott - Think lap race... it would be cool to be able to use multi-playback to simultaneously view different laps within a single gpx file so you could more easily visually compare the laps.
Or... if there were a way to easily delete all of the points that are not part of a specific lap then it wouldn't be to hard to split it into multiple gpx files, each containing a single lap, and use the existing multi-playback functionality.
Maybe this is already possible some way that I haven't figured out.
Thanks,
Toby