I have a ps3, and I have been playing a ps2 game (Final Fantasy X, best game evar) and its saved onto my ps3. I was wondering if it was possible to copy that saved file onto my flashdrive and take it to someones house so that I could play that saved game on their ps3. I'm just wondering if it could work, cause I really don't want to have to buy anything. Thanks!

Yes you can. Just plug the drive into a USB port, give the PS3 a minute to recognize the drive, then go to memory management near the top of the game menu and copy the save over. You will have to copy the save from the flash drive to the new PS3, but that is basically the same steps, just under the flash drive's memory.

You could also use one of the other memory slots with something like a photo-card for instance.

Important note: not every, or even most, PS3 models can play PS2 games. I would make sure your friend's can before you bother transferring the save.