I want to get a Garminfone and a Samsung Vibrant from eBay new-in-box or used. Do I need to do anything special or will there be any hurdles I have to go through besides just sticking the SIM card in for it to work? Also, I hear a lot about cheaper data plans. Can I use a dumbphone to sign up for the $10 web plan and then stick the SIM card back into the Garminfone or Vibrant and have it work? Do I need to do any special configuration?