Phone that says 'I can't talk, I'm not in the mood'

Scientists are making an "intelligent" mobile phone capable of blocking incoming calls depending on the owner's mood.

Using "context aware" technology the "Sensay" phone will monitor calls and send back polite messages saying the user may be contacted later.

An early prototype uses an armband and belt-worn box fitted with sensors to build a profile of the owner's situation.

Researchers at the Institute for Complex Engineering Systems at Carnegie Mellon University in Pittsburgh, Pennsylvania say thatif the phone senses the user is busy it might block an incoming call.

It would send back a message to say the user is unavailable but if the matter is urgent the caller can try again in three minutes. If a call from the same person was received within that time, the phone would put it through.

The researchers are interested in four basic different states - busy and not to be interrupted, physically active, idle, and "normal". Most people change between these states an average of six to 12 times a day.