Haier known for their Pen phone has another tiny GSM phone on the market that is not much bigger than a lipstick case.

The Haier Elegance measures only 3.5" L x 1 1/4" W x 3/4" D (90x35x17.8mm) and weighs 2.24 oz (64g).
Haier still was able to pack tons of features into the shiny and small phone. Features include 1.1 inch color OLED screen, MP3 player, FM radio, micro SD up to 1GB supported, Bluetooth, games and alarm clock.
The tiny phone has a standby time Up to 200 hours, a talk time up to 3 hours and a media play time of up to 11 hours. The Haier Elegance comes in two versions. The YMP-3190 is a tri-band GSM phone supporting 900/1800/1900mhz, ideal for travelers. The YMP-3850 supports 850/1900mhz frequencies necessary for U.S. use.

The unlocked Haier YMP-3190 and the YMP-3850 sell each for $229.95 on the Haier Elegance site. Looks like the shop ships international.