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!"
There is a unit in Kona Hawaii that we found fantastic. It had over 600 points of interest and every public restroom anywhere near a highway. The island is so big and the Hawaiian words all look the same after while. Tour Guide Hawaii was simple to use and very helpful to us in creating our own vacation our way, and at 22.00 per day, it was very affordable. Next time we go to Kona, we will definitely get one again.
Check out http://www.geovative.com where you can create your own tours with audio, image, and text descriptions and then download them to your GPS device!