I'm admittedly an OK Go noob so I've kind of been wondering what they sound like live. Well thanks to an update I just saw from their Facebook account I now know. That's right...get a free download for a live version of White Knuckles. The only catch is that you need to have a Twitter account.
http://okgo.promojam.com/promotions/giveaway/authorization/new
Oh and the answer to my question of how they sound live...really really good. Here's their live performance on last night's Late Late Show with Craig Ferguson as further evidence. Also anyone in the Kansas City area should check out their free concert at the Midland this Saturday (they're big fans of the whole free concept apparently).