Is there a free computer station on the ship that I can use to upload my picture from my camera to a potable hard drive?
None of the computer/server stations onboard have accessible USB ports. Carnival's onboard photography dept would be only too happy to transfer your pics/files from your digital camera to CD, for a fee ofcourse!
I may stand corrected but I think they charge something like $29.95 for that service. You would be better off carrying a few extra memory cards,
a 2GB SD can very easily be purchased for under $20 nowadays.