Let the hive mind of Engadget get that for you.
"As someone who doesn't reside in the USA, I was wondering what would be the best way to get internet for my computer in the US for a couple of weeks? If it were Europe I know I'd look for some prepaid data. Is there anything similar offered by American carriers? A MiFi or a data SIM that I can tether from would work, but I'm trying to maintain a tight budget. Help!"
Holy crap balls! An engadget story kinda sort of about me. Prof Spletzer was my advisor at Lehigh for my masters. I worked with them on this! (Sort of) I am on their lab page.
http://vader.cse.lehigh.edu/people.php