This is really cool, and really, really illegal, like federal illegal, pound-in-the-ass illegal. Even owning such a hacked Droid is probably illegal, because it

This is really cool, and really, really illegal, like federal illegal, pound-in-the-ass illegal. Even owning such a hacked Droid is probably illegal, because it's unlicensed equipment that can use restricted spectrum. If you use it in a large metropolis, I'd expect you'd interfere with other operators basestations, and as soon as they figure it out, they'd be on you. And the FBI. Maybe the SWAT. Keep in mind that the GSM/CDMA spectrum was auctioned for billions to the operators. Update: someone mentioned a "developer's license" - a bit of research turns out something even better - some countries, like the Netherlands, allow unlicensed very-low-power base stations, up to 100mW, essentially pico- and femto-cells. Many Wifi routers have higher TX power than that. This will cover a room, a large hall, or an open air space large like a football stadium. No mention of a developer's license though, as this seems to cover its needs.