For a fairly old device now, which can be picked up for around £40, the Sony mn2 is a very useful extension of the powerhouse that is your phone. Many tasks can be achieved on the watch, just requiring the data connection and Bluetooth of the phone to supply information to the watch. As seen above, texts can be written and sent, galleries viewed, even web browsed (providing your fingers are small enough of course!) without even touching your valuable handset.
A must for Xperia phones.