Is it possible to not have a data plan for my AT&T iPhone?

I have Wi-Fi I can use almost everywhere I go, and I don't need it when I'm driving. I think having to pay that much a month for something I don't need is ridiculous. I actually have data turned off on my phone.

Added (1). I need it for calling and text, but not the 3G data.

You mean using it as an ipod? You can do that. I've done it in the past.