...it's not the best way to go. If you want to download pics to your PC, you're better off owning a cheaper and more portable card reader, which just slips into any computer's USB port and accepts the memory card from the camera, using the PC's power to do the image transferring.
I don't think this gadget makes sense unless you are planning on shooting while plugged into a wall socket or unless you are planning on running a slide show directly from your digicam to a TV/monitor.