Is it possible to make a service like this?
1) you make the account on the service
2) the service gives you code (example: 34757893368) and a phone number.
3) you go out and buy a phone card ( it's usable on phone boxes )
4) you insert the phone card on a phone box
5) you call the phone number given by the service
6) you insert the code: 34757893368
7) the service will instantly empty the phone card and will convert the money in bitcoin on the account.