Some of those have a chip in a small board. 29 bucks sounds not so bad for a feature where you don't have to lug around a PC.
I have just purchased a Sony HDR-XR260VE Handicam which has a Hard Disk. There is provision for downloading the videos from the hard disk in the camera to an external portable hard disk. It is necessary to purchase a connector from the them at $AU29 which plugs into the usb mini b ouput port and has a female standard usb connector on the other end. Before I eventually purchased the Sony connector I tried using a number of different combinations of connectors and found that none of them work. It is possible that Sony may have intentionally crossed wires in their usb mini b output and that this is corrected in the lead they sell. However I wondered if anyone has found a combination that works - may save others from having to spend $AU29.00