InkWell and Trackpads
Many users have noted a MacOSRumors blurb about the possible use of InkWell:
When you ponder the purpose of Apple's forthcoming InkWell handwriting-recognition technology, think about the way the trackpad works on PowerBooks and iBooks. Imagine if you could add an inexpensive stylus pen, and enter text much the same way it is done on the trackpad-like area of a Palm handheld or similar device
The problem with this is that current iBook/PowerBook trackpads don't register the movements of a Pen/Stylus (only our finger)... so while, this is certainly a possibility, it would only work on updated hardware. This appears to be entirely speculation.