I have mentioned these guys before. FreedomPop is a company that offers free wireless 4G Internet access using cell phone networks. The base offering is 500Mb of data a month for free.
Well this has been a bit limiting since the 4G Sprint network is only available in select cities. According to CNET, FreedomPop is now offering a $40 3G/4G hotspot that gives you nationwide 3G access. And of course, you get the 4G where it is available. The pricing is a bit confusing but is still a great deal. You can pay $0.02 per Mb for data above the 500Gb on the free plan. Which works out to $20 per gigabyte. Definitely worth checking out.