Don't buy a Seagate one. We bought a 500 gig Seagate model at Sam's club for cheap at work for the production guys to use as a back up (why they need a backup for a 4 terrabyte raid is beyond me) and it failed within days. Reading on amazon suggested they have frequent failures of this sort.

It looked a lot like this 400 gig model (http://www.amazon.com/Seagate-ST3400601U2-RK-External-Hard-Drive/dp/B000BT4BVY/ref=pd_bbs_sr_10/002-8511872-4926447?ie=UTF8&s=electronics&qid=1187878070&sr=8-10), though that 400 gig model seems ot have good user reviews.