Normally I do an entire shoot on one SD card and then use Disk Utility in OSX to make an disk image of it for archive later. However, on this last shoot I brought the wrong size cards and had to use three different ones. Is there a way to combined all the media files under one folder either through the Finder or another program?

My master plan was to just copy files to the camera's memory (HFS10) and then move the files back to a larger card, but the camera only allows camera to SD card copying and not the other way around.

Any suggestions?

Brian, can you not simply put the cards in a USB reader and drop them all straight into a widows explorer folder ? I never use the terrible program that Canon suggests. Just simply put the card in the reader and look / navigate :-
Canon (x:) / Private / AVCHD / BDMV / STREAM. Then highlight & drag to your folder.

RonC.