Visiting the US - pre-paid data sim card?

I'm live in Norway, and this summer I'm going to spent a couple of weeks in the U.S visiting some relatives. It would be nice to be able to check my email, facebook, look up directions and so on while I'm there without spending huge amounts of money roaming on my norwegian data plan, so I was wondering if it's possible to purchase a pre-paid sim card I could put in my phone or a second phone to achieve cheaper data roaming while I'm there?