The annual Defcon hacking meetup produces its share of unique creations. You know you're in for something special when even your entrance badge is an adventure. Defcon 20 might be winding to a close, but about 650 guests may just have the fondest memory of all: access to a private, ad hoc GSM carrier from Ninja Networks. While the collective's Ninja Tel is really an invitation to a party at the Rio Hotel, where the lone cell site operates out of a van, it lets the privileged few call and text each other to their hearts' content over cellular and WiFi. The network operators can unsurprisingly eavesdrop on any of the completely unencrypted calls -- this is a hacker's convention, after all -- but we don't think guests mind after getting an equally rare, customized HTC One V for free to make the calls in question. The Android 4.0 phone gets unique perks like triggering a nearby vending machine with Qualcomm's AllJoyn or making apps on the spot through Google's Integrated Development Environment. Owners can even reflash the One V to hop on AT&T or T-Mobile afterwards. Just don't expect to see Ninja Tel popping up in your hometown anytime soon; when Defcon shuts its doors, the cellular network shuts down.