I have an iPhone 3g running the 3.1 firmware and the 5.11.07 baseband. It's jailbroken, and I have it without a data plan. I picked the phone up from ebay and just popped my sim card into it. The phone and wifi work fine, but the SMS doesn't seem to send or receive. I also don't have the camera icon (for MMS) even though I installed the latest carrier update. Do you need a formal texting plan for iPhone?
Is there a way to manually enter an SMS server, or will it still not work? I didn't realize you can't use pay-per-service texting with the iPhone. Doh!