What are some cheap, inexpensive Internet plans for the iPhone 4?

I want Internet only everywhere

I would suggest a data sim.

Just visit your networks site and purchase a data sim for a iPad.

Hope this helps

The cheapest plan I know of is from Virgin Mobile. $35 a month for 300 minutes voice, unlimited text and unlimited data (but throttled after 2.5GB). The only thing is you have to buy the iphone from VM. However if you do the math, full price for the phone + 2 years service is hundreds of dollars less than ATT, Verizon, Sprint.