I'm an expereinced Palm user and a registered, though now inactive, Palm developer. Most of my life organisation is in that handheld, but I am very aware of it's limitations, too.
After sampling a lot of aviation programs, I'm forced to admit that doing that sort of stuff on your palm is a bit like so many other things we try to do on computers, easier the old fashioned way.
There is really only one program I use for my aviation needs - some kind of good database software. Just put together exactly what you need. I use HanDBase, there are others, that's just personal preference. For example, I sampled a lot of logbook programs, none were quite right, then wrote one of my own, and it was too slow. So I took half an hour to put it together on HanDBase, and am using still. Drop down lists are a snap to create, get it write and you'll use minimum Graffitti. Synchronises to a desktop version, which is like an easier to use Access. Main limitation is very limited math.
I also use this software for a very comprehensive index to regulatory and operational documentation, and to replace my "good stuff" notebook, as well as a multitude of other non aviation databases.
Cost per use, and ease of use, make it hard to beat.
Not to say there isn't other great stuff out there, but since I went down this road, I haven't bothered to look much any more.....
Cheers