The palm I currently use (I've been using one for too many years to count) is the Palm TX. It is a nice machine that has everything, and I mean everything I need on it. The application I have found most useful is no longer being sold and can't be found anywhere, this is commonly known as abandonware. The app name is TecSync, an application for people who need to keep track of a lot of computers - which describes a good portion of my job.
A ways back I was on one of the Palm forums (brighthand.com) and realized that I was answering a lot of questions about the same or similar things, so I created a set of webpages that lisited all the applications on my palm with links to most of them and explanations. I collected helpful links from other members of the forum (you'll see there screen names listed in the thanks section) and put those in a helpful links section.
All in all the whole endeavor was enlightening and I now have a resource I point to quite often.
Check out the page either by clicking on the title of this article or by going to this page.