I would jailbreak,unlock, and activate it with iLiberty+ or Pwng then you can put any GSM SIM card in it, disable the Edge network either with Boss Pref's or SSH into the phone and change a bit of the code. I did the latter but it's not recommended if your not sure about what your doing.
If you don't have a data plan then they just charge you by the amount of data transferred through Edge. Hence the disabling.Once it's disabled you just get a "could notconnect to Edge network" message and no large bills either.
