instructions are here:
http://www.facebook.com/kindle?sk=app_172341942779663
i can't enter since i'm not a US resident (and already bought my kindle anyway, so I don't want to dip my hand in and ruin someone else's chances; that's just selfish), but I thought that those here might be interested.
(and I decided not to put this in the Kindle forum since I think most people there already /have/ a kindle).