there will be internet caf�s all over the US; I really would not risk taking my lappie with me. *If* you decide to do so check you have it insured with your travel ins/contents ins
AFAIK all you should need is the right adapter so you can plug it in over there. As for getting a broadband deal before you go, I would have thought your hotel would have wireless? Or in any case there will be hot spots around that you can 'piggy back'