Depends if you want USB to provide power, or what you're using the drive for. I'd go to dealmac.com and find a name brand on sale. If you're looking for extra storage on the go, I'd recommend trying to upgrade the drive in your MBP instead of hauling around an external.
by portable i mean power from usb and easy to carry around... Also if you upgrade you hard drive in a mbp doesn't that void the warranty? I need a 160 gb... I guess i should rephrase the question i just wanted to see everyone's discussion, so i need a portable 160 gb external drive. What is the best drive for under 150?
I keep having these things die on me so I'm getting the most solid one I can find: The Lacie Rugged 160GB FW800 - encased in aluminium with rubber shock absorbers. If it's for you backup data, it's worth the 200 dollars.