I recently went out to buy a cordless phone. Very few shops were selling that. Instead, nearly all shops had mobile phones. It was a bit annoying. But then I thought, it would be really cool to have a base station, like that of normal cordless phones, but one which could be calibrated with a specific mobile phone - preferrably by installing some s/w in the phone which gave it a certain signature.Not preferable, and marginally tougher, might be installing somehow onto the mobile too, which could give it a unique signal or something.