At a recent exhibition I played with a few of the PDA-based aviation goodies.
They're certainly all very well meant, but many of them have user interfaces that may not be terribly good for in-flight use.
For example, one program for doing checklists, made use of the standard PalmOS checkbox, which is pretty small, and requires a stylus to use accurately. I wouldn't use that in the air, personally. Another checklist program used big "finger sized" buttons (rather like the PalmOS Calculator program), which was far better from a useability standpoint IMHO.
I make the same criticism of the GPS programs that I saw. I'm sure they work well, but I worry about useability. In addition, I worry about the Palm or PocketPC reliability. For example, my PalmV (with a paltry 2MB of RAM) runs slowly when the memory is nearly filled up and sometimes requires a hard reset. Similarly, when the batteries are below 50%, power management quite aggressively throttles back the CPU, causing slow-down. Now, in flight, I would imagine that these things are plumbed into the aircraft power somehow, so presumably power management is no longer an issue.
Don't get me wrong - I think they're useful and great fun, but how do they compare with a purpose built device with physical buttons to operate system functions, etc?
I fly with neither, so I wouldn't know, but am interested.
In any event, no one is using these for primary navigation are they?
