If you got an old Windows Mobile phone with resistive screen and enviously glare at the people that have multitouch on their new phones with capacitive screens, there is now hope!
Adel Al Zubeir figured out a way to calculate different gestures form the input you get from dualtouch on the screen, and can figure out if you pinch to zoom or rotate among other things. Check the vid below for a look at how it handles rotation.
If you are a developer and want to use this in your apps there is an SDK for it made available on windowsphoneme.com and you can get it
Resistive screen multi touch