Hello Blueloo:
I use my HP Jornada 545 all the time for flying, particularly at the flight planning stage. I don't use PocketPC in a active role whilst actually flying eg GPS flight tracking as I find it pretty hard to read in bright conditions. But I wouldn't fly anywhere without it.
A program that I can highly recommend is FlightCalc which is produced by a Canadian firm called Skymark Technologies (
www.skymarktechnologies.com). I've tried a number of other programs but this one really works for me as it can do all flight planning calculations, graphical presentation of W&B etc.
There are many pilot and flight training applications available for both the PocketPC and PalmOS operating systems. The best way to find applications is to go to
www.handango.com and go to the relevant OS section and then type either "aviation", "flight" or "pilot" in the search box. A list of applications will then appear which, in most cases, are available on a trial basis for 30 days.
Handango appears to be the better site for PocketPC applications while the Tucows website (
www.tucows.com) appears to cater better for Palm PCs.
Hope this helps!