The Sony Ericsson MBW-100 is a watch that works with your phone to show the numbers of your incoming call numbers and even vibrates when the call or a message is received.

The watch looks pretty cool, but is it a good idea or a bad one?

The chances are if you think you need the watch, your phone will probably not be that far away anyway. It's not as if it works Dick Tracy style as an alternative to a headset, and the display is too small to make it a suitable method for reading your text messages.