In 2005 sparkfun has posted a article on hacking a retro rotary phone into a mobile phone. This year they have made it commercial and available for sale at $499. The red version is available now on their store. Not cheap but that the price you need to pay for a "unique" mobile phone.

The red Portable Rotary Phone, now in Red! Phone comes fully assembled and tested. You can insert your SIM card, and use it as a normal mobile phone! The phone will read your phone number and account minutes. Phone dials out like normal through the rotary. Incoming calls ring the original, loud, gong style metal bells. Sparkfun also admits that the sound quality will not be as good as your pocket phone. Buy it at your own risk! The GM862 cellular module from Telit works within any country that has one of the 900MHz/1800MHz/1900MHz cellular bands (90% of the world). The battery can run the phone for 4-5 days and is charged by unscrewing two screws on the bottom of the phone, opening it, and attaching the charger.

The Rotary Phone comes with:

• Main controller board
• Ringer module
• 2000mAh Lithium-Polymer battery
• Li-Po battery charger (3-prong 110V and international 220V)
• Mini-cellular internal antenna (compatible with North American and European Frequencies)
• GM862 cellular module

http://www.sparkfun.com/commerce/product_info.php?products_id=287

http://www.sparkfun.com/tutorial/Port-O-Rotary/portable-rotary.htm