I've been after a usb drive caddy for some time, wanting something I could use as an on the go backup for my laptop, bulk file shifter and just general big bit of space to chuck stuff.
Went for the Thecus Yes Nano N1050 which does all the above plus gives you this nifty on the go feature where I can plug in a little battery pack to give it some juice (4xAA's), connect my camera lead to it, press a button and it copies all the files from my camera to a new incremental folder.
I got it from Scan who had it on a bundle special along with a 100GB Samsung drive last week. I didn't have any spare 2.5" laptop drives so thought I'd go the whole hog.
Power requirements are very low, I've plugged it into my Asus laptop, numerous pc's, my Infrant ReadyNas box and no complaints from any of them. It comes with a lead to provide power from a second usb port if required but I think that'll remain in my bag.
The only small gotcha is that for the "on the go" copy function to work your drive must be formatted to FAT32 (I assume the controller board only talks to this format). WindowsXP by default will not format large drives (above 32GB) to this so I found a great little utility called Fat32Format from Ridgecrop which does it for ya, and very quickly at that!