I've seen anecdotally a lot of use for cross-border payments. (Try wiring $500 to grandma, and see how many middlemen take a share)
I used to use Xoom but every six months when I'd go to do a transfer they'd need more security verification and it got tiresome. Although that was a few years ago, maybe it is better now.
http://web.archive.org/web/19990508170650/http://www.xoom.co...