I tried out the Canon G9 with CHDK Ultra Intervalometer script capturing HD-sized images to put together an HD time lapse on a recent trip to Seattle. It was freezing cold out there with a big wind coming off the sound. The G9 was perched on a GorillaPod, so I figured it would be flapping around in the wind, but it turned out to be pretty steady.
My only gripe about this setup is that the G9 maxes out at about 0.7fps. I'm gonna have to try this out with the 5D so I can get 2-3fps.
Images were converted using Linux 'convert' command with sharpening and scaling, sometimes contrast and saturation enhancement. Images were merged into video using mencoder:
mencoder -nosound mf://*_tovid.jpg -mf fps=15 -ovc lavc -lavcopts vcodec=msmpeg4v2:vbitrate=4800 -o time_lapse-test.avi