[citation][nom]twisted politiks[/nom]it will be pretty easy to pick up the wireless signal your phone is transmitting, and copy it to go into the room.[/citation]
Actually, not so at all. The connection will most likely be encrypted, and "that signal" would only work once, in a handshake context. The idea is not bad at all, probably someday all your keys, money, IDs etc. will pe stored on some electronic device, be it smartphone or something else. The biggest problem wouldn't be security, but simply making all the checkpoints and devices that can read the stuff everywhere. So prolly still 20-30 years away.