Well here is the Samsung SCH-S310 recently unveiled in Korea. What's special about this phone is the built-in 'Accelerometer' which can accurately calculate and ascertain movement in three dimensional space and then carry out commands according to those calculations. So you would write a '0' by moving the phone in that pattern and it will pick it up as such as an input.

It would be fascinating to see how the interfaces for phones evolve with the use of spatial recognition technology they employ in this new Samsung phone. You can check out the full story at BusinessWire.