From the last topic of thunderbolt I went and got a usb 3.0 enclosure. It's stainless steel with a rubber band type outline, it's very durable and looks nice, for $19.99. Its also bus powered. I put in a 128 gb samsung 830 in it, and benchmarked it. I also benchmarked my old main laptop external, a bus powered Western Digital my passport 256 drive I got from target for $29.99.
Here is the passport:
I believe it's 7200 rpm. It never seemed horribly slow, I mean it did take a little bit to load sometimes..
Here is the usb 3.0 drive:
Now this is slow for a samsung 830, but it's pretty good for external and bus-powered. I'll later benchmark on a usb 2.0 only port.
Going back to the earlier topic, the usb 3.0 enclosure is $80 cheaper (Most are even less), and this can be used with far more then thunderbolt can. Thunderbolt would give the samsung 830 more speed, but not too much for $80 more, and you sacrifice being able to use the drive on any machine with usb.
Until thunderbolt gets a bit more exposure it's better to go usb 3.0.