I’ve had a Palm m105 for a couple of months now, and I’ve started to rely on the little thing. However, I haven’t added many apps so far. There are just so many out there, and I can’t decide what’s worth the memory space (and, if it isn’t freeware, the cost).
So, what is everyone’s favorite applications for their handheld? Personally, I only care about Palm OS things, but if you have anything to say about PocketPC or some other system, feel free.
I don’t think they have a Palm version (I have a PocketPC), but AudiblePlayer is my favorite. I can download npr shows that I’ve missed, and listen to them whenever I want, provided I have enough extra memory. My PocketPC has replaced my old mp3 player in this regard.
It really depends on what you, when and where you use the Palm. I find that AvantGo is my most frequently used application. Every time you HotSync it automatically retrieves updated files on specified web sites. I use it read articles from NY Times, Wired, etc., and of courece Cecil’s columns.
I also use DateBk4 from Pimlico Software which is an extention to the built-in datebook and todo list. It displays both on the same page, and do other useful things. ActionNames is another similar software which some people prefer.
Outliner programs are very useful on PDAs in my experience. I use ShadowPlan. There are a few other good ones out there. You can use them for checklists, making outlines for presentations or any written work, project management, or just taking notes.
One neat program I recently found is theFXPilot currency conversion program. Every time you HotSync, it automatically retrieves the latest exchange rates from the server. I don’t use it that often but it’s handy when travelling or purchasing from overseas mail order companies.
There are tons more software. I suggest looking through thePalmGear web site.
By the way I don’t think the m105 has audio capabilities, so Audible is out. But I agree it’s a pretty neat service. I use a separate device (Rio 500) for that. Personally I like having them separate - if I drain the PDA battery by listening to Audible I might be in trouble for the rest of the day.
Of course, you will not be able to live without downloading and installing the tricorder application for Palm platforms… 
JOhn.