I very recently began to start playing at walker poker that accepts U.S. players. This site is pretty great IMO and I would check it out.
The low stakes games are great, there's an okay amount of traffic and not to many sharks swimming here just yet.
The software is very nice, I would compare it to ultimate bet's even as well as full tilt's.
Right now walker is not a very big site, but it should be on the rise seeing such a nice U.S. allowing site developed. Also, when your all-in in any type of game it shows the percentages to win which I am also fond of.
Not many bad things to say about it, unless your a big MTT player because you won't find the $24+2, 500-1000 entrants here, considering this site is still on the rise.
Check it out if you want, you may even find a no-deposit bonus to begin playing on there with a free bankroll. Good luck.