Re: check this touchpad out
Best buy had one on display last time I went there, and I found it pretty terrible. The surface just doesn't feel right to me. Otherwise it seems like an okay device, but I'd recommend trying it before purchasing one, or at the very least buying from somewhere with a good return policy.
I don't really see the appeal of using an external trackpad. I have one of the wacom tablets with touch entry, and it never gets any use because a trackball or mouse is simply better.