I'm a little uneducated about what and how SIM cards work, especially in cell phones which is bad since I'm currently trying to figure out how to make the switch to an unlimited data only cell phone. I have WiFi at home and that's the main place I talk to people, so using VOIP wouldn't be a problem. I'm wondering if I'm going to have to just get a tablet and data plan for that or is there a way to convert my AT&T iPhone 3Gs to a data only device? Or I guess I could get an iPod Touch, but that'd only have web access on WiFi, not ideal. Are there any data only plans for mobile devices, new or converted? -- I haven't found any...