service that I think someone at a game shop should provide
Memory card backup. Plug your Gamecube or PS2 card into the reader, wait a minute, get a CD burned with the data. The reverse service is also available. Make it cheap or free (if you provide the blank CD).
Maybe even the same thing with XBox - we take your xbox, run one of the temporary hacks on it, dump the savegame portions of the hard drive.