Best U.S. phone plan for data, with tethering?

Hello,

I'm going to be in the US for a month, and I have a Galaxy Nexus (GSM). Everyone just recommends to buy a local sim card, and thats what I plan to do.

However, I'm lost as to what to buy. My plan at home is only 2GB a month and usually that suits me fine, but I will likely need more, and hopefully will use tethering (am considering using an "unofficial" android app if anyone recommends one).

Many people lead me to Simple Mobile for their $40 unlimited plan which looks quite good, but are there any other better deals (with better value for money)?

Thanks