I use simbase. It is pay as you go and uses verizon, at&t and t-mobile. It will use whichever provider has the best reception in your work area. You can also assign static ip's at will for $0.30 per day, but you can cancel anytime. I think the overall cost is $0.02 per day for the sim and $0.01 per MB of data. I hace one on my LS+ and it works fine.