Haier Elegance World's Smallest Phone

The "World's Smallest' claim comes with some qualification. It is in fact the "World's smallest GSM phone featuring an MP3 player", but it's still pretty tiny.
The Haier Elegance measures 9.1 x 3.5 x 1.8cm (3.6 inches long) and manages to pack a lot of gizmos into its diminutive case. MP3 player (128MB, expandable by 1GB via Micro SD), FM tuner, Stereo Bluetooth, 1.1 inch full color OLED display and Tri-Band GSM.