I don't think there's any danger of bending contacts on SD cards, and nearly every camera automatically turns itself off when you open the door that covers the card slot. Of course, if there's not a cover, you can just yank it, but it should be no different than pulling out a floppy disk while it's being written to (or a USB drive) - you'll probably get some lost clusters and the last file will be useless, but as long as chkdsk/scandisk is run ASAP on it, everything else should be just fine.
Flash memory is probably the most reliable place for the data (outside of a tape backup), but it's still not bulletproof, as we all know.
yrdlyprincess, burning them to a CD there is slow and expensive - and remember, if you want to dump a 2gb card to CD, that's three CDs that will have to be burnt. That'll get really expensive fast. (I think it's around $13 on site to burn the CDs, to say nothing of the time wasted waiting for it. So $39 for 2 gb worth - that's a good bit more than just buying another card!)
Other options are bringing a laptop with a CD/DVD burner and burning copies yourself, or there are standalone devices that will copy your memory card to a hard drive. Hard drives are the least reliable places for data though, so ideally you'd have two identical setups, for redundancy.
Flash memory is pretty reliable. You hear more stories of people dropping or forgetting their multiple memory cards than you hear about flash failures.
