Offload shots to portable USB drive?

Does anyone know if you can offload digital camera shots onto one of the key chain-size (flash memory) USB drives?

I'm not sure if the transfer requires that the files be "pulled" by the PC, or if the cameras are capable of "pushing" the files.

Will be traveling abroad for several weeks and would like to mail files back periodically for safe keeping, as e-mail may not be readily available.

The other alternative is, of course, extra flash cards, but thought I'd find out about the pocket USB drives.

Thanks! ~Carol in Detroit

There are devices that transfer files from smart media and other memory cards onto an on board harddrive, like the archos multimedia junkebox. But those stuff typically costs a lot.