this is probably my favourite external drive so far, super compact and very fast.
picked one up for 299 while it was on sale for 512gb
http://www.angelbird.com/en/conf/ssd2go-pocket-662/
also have a lacie rugged TB drive with samsung 840 evo ssd i use between my macbook and iMac since my iMac has no usb 3.0 yet
The Samsung T1 is phenomenal, my workplace has 25 of them (one for each person in the software dev team) and so far we're all really stoked about it.
Myself, I use a Samsung T1 500GB along with a Transcend 960GB JetDrive.
There's one thing worth noting though about USB-based external SSDs - random performance is really far off when compared to the same drive connected over SATA3 or PCIe, but it's fast enough for most needs.
Has anyone used both the SSD2Go and the T1? Comments/comparison?