I love that too, on a Tablet PC. The Ink support of Windows makes this possible. Unfortunately, on the Pocket PC platform there is no support for Ink, which would us require to implement the functionality of our own. And hand writing on the small display of a Pocket PC device is another challenge. Even on the much bigger Tablet PC, I sometimes struggle with the available screen estate when taking handwritten notes.
Other functionality, like the IncFinder (and other search functionality) would also suffer from handwriting (at least if it is not automatically converted into text in the background). I fear the current generation of devices is lacking power to do so.
But we like the idea as well and will keep an eye on it.
Best wishes
Rolf