Been looking for one myself.
I couldn't recommend a particular brand but I would say get a 2.5 inch drive that CAN BE POWERED FROM THE USB or FIREWIRE. It's a lot more convenient. For best compatibility, I would recommend USB since it's already on most machines built within the last few years.
Might get a better deal if you buy the hard drive enclosure separately from the hard drive although the prices on 30-40GB drives across the board seem to have dropped quite a bit recently. If you do purchase them separately, you might have to make sure that the particular hard drive does not require more power than what can be supplied from the port.
Just don't get an external 3.5 inch drive. I got one of them and It's a pain to carry it around because of the bulky power-supply.
Edited by Burgin (29/07/2002 17:03)