What kind of Internet plan is required to an unlocked iPhone on T-Mobile?

I plan to do an unlocked iPhone 2G I and T-Mobile. I want to be able to use the Internet on the iPhone, but I'm not sure what plan I should use because I do not want to have additional fees for using the Internet. Do I get a BlackBerry Internet plan? Sidekick? G1? If you Please help!

you can not get the sidekick plan on the phone .. because the acolytes have their own tricks .. sense a different signal. the G1 and the BlackBerry seems to me as if the internet is the internet PDA. they have the Internet at low prices .. I do not think it can be sufficient to the phone .. thephone Fi is also .. you should not waste your money if you can pick up some free places.

T-Mobile myTouch 4G “Piggyback”