It's a cool hack, but with 32 bit ARM chips as cheap as they are, I'm a bit skeptical that anyone really wants an 8-bit phone that's "only" a phone when you can get a smartphone for a similar hardware cost.<p>Also, I'm trying to envision the slice of the world that simultaneously cares about an "open source" cell phone, but doesn't want a full featured smart phone. Maybe people like that exist, but I certainly don't know any of them (I know that doesn't prove anything, just saying...)<p>One application I think would be pretty cool for this would be some kind of remote monitoring, or remote controlled device - if you could get an SMS plan with that shield and then hook up sensors/actuators to the arduino, you could potentially get data off it via SMS, or control it remotely via SMS. That would be cool.