$40/mo unlm Internet, text and calls and no contract - Simple Mobile SIM card for $0.31 + free shipping
I dont't know why Simple Mobile isn't more popular than the sponsored deal for Straight Talk. Not only is the SIM card $0.31 with free shipping, service with 250mb of 4G Internet and unlimited 3G Internet, unlimited SMS and MMS and unlimited calls with no contract is only $40/mo.
I used it with my LG G2X and currently use it with an iPhone 3GS. It's not the fastest, but it's cheap!
I also pay $45/mo for 2gb of data on my iPad with no contract. I don't see on their website where they mention it works with iPads, but it does, call them and they'll help you program it if needed.