Does anyone know of any flight planning software for PDAs...
If you want a low tech/cost approach there is CoPilot. It is shareware and runs fine on my Palm Zire. I used it mainly to check my work for PPL training, but it is nice just to pull it out and see how long it would take to fly to Perth, or how much time I would save flying one type against another. Haven't tried to output a flight plan from it though, but you can. Have to find youself some waypoints too.
http://lauriedavis9.tripod.com/copilot/