Here is the HTC Flyers active digitizer (pen):
http://armdevices.net/2011/02/19/htc...ndroid-tablet/

It shows how having your hand on the screen doesn't affect the writing.

The input lag is somewhat disappointing. Optimization people!

I looks good, but seems like a rather gimmicky implementation. I have doubts that it will be well supported by applications, but I hope that I'm wrong.