Flash sounds like the way to go especially hearing about the compact flash and 40 pin connecter. i know this goes against what i just said but it may help. hitachi makes a hard drive
CF card (if you think about this for a second and think about the "compact
flash part it doesnt really make sense since its a hard drive) it has a really high shock protection and may be eaiser to shield from vibrations. cons are its kinda pricey----if it works you could start a lawn mowing business and profit on it.