|Can you see the pics when the card is in your camera? |
If yes, leave the card in there and connect your camera to your computer (you may have to install the Canon "Zoom Browser" I think it's called (my current DSLR is an Olympus model so I'm relying purely on memory there).
I don't know what else to suggest, but believe me I've been there, not a nice feeling.
At least with a film camera you might have lost a couple of shots that weren't exposed right, very rarely did you lose the entire 24 or 36 shots. Progress does have it's bad points.