I experimented using my Sony T50 to shoot footage while on the move. It sort of works, except that the camera records in 640x480 25 fps and uses MPEG1 codec that encodes at nearly 3000 kbps (366.8 kBps), so a 512 MB card can only record ~22 minutes -- not enough for my daily commute to work.
I can increase the recording time by using a higher capacity card. However, I'm curious to know if there are other cameras that offers 640x480 15 ips (40% savings) or can encode more efficiently, by using MPEG4 for example. If got MPEG4 AVC, that's the best!
I'm more interested in cameras that offer 640x480 than those with 320x240 cos it's already pretty hard to make out the details -- like number plates -- at 640x480.