Actually, I take that back; these are official unlocked devices, not gray market (I think).

Great chart of what unlocked iPhone 4s cost in various countries, some of which don’t have official sales channels. http://bit.ly/99oyyT

@MichaelALim I’ve used it on Linksys routers previously. This is the first time I’ve tried in on a dual band router.

Just put DD-WRT on a $30 refurb dual-radio netgear router. Built-in firmware flakey on 5 GHz; DD-WRT rock solid. Great software.