Hi Guenter.
in this paper:
http://gige.xdv.org/pda/ICMC2003.pdf
you mention two "alternate" ways of controlling PDa: a serial connection to external controllers and gestural/handwriting recognition. I was wondering if you could provide a bit more information about the second (handwriting recognition) and perhaps some known implementations on the IPAQ of the former (serial input).
I've been investigating GPS input via Bluetooth/serial connection, and Joel Ryan at STEIM says he used IPAQs a while ago as wireless relays for accelerometers attached to dancers (this was before they got into hacking wireless game controllers, a technique they have really perfected as of late!), so there's at least a couple of known implementations from my end.
best, derek