From our friends over at PalmAddict a review of Quickipedia (http://palmaddict.typepad.com/palmaddicts/2006/01/quickipedia.html), a dedicated Wikipedia reader for Palm OS:
Another Wikipidia reader? After all we've got Genius. I can read Wikipedia in my Treo 650 browser or even use the PDA optimized Wapipedia. So what's the big deal? Well, I decided to download it and found, to my surprise, that there is a lot of value-added to this application and I certainly will keep it on my machine.

UPDATE: PalmAddcts has another article (http://palmaddict.typepad.com/palmaddicts/2006/01/quickipedia_off.html) on this product.

The official blurb (http://standalone.com/palmos/quickipedia/):
Quickipedia for Palm OS is a handheld client for accessing and reading the Wikipedia online encyclopedia. Wikipedia contains over 900,000 entries on everything from history to popular culture in a number of languages, making it perfect for educational purposes or for those seeking general knowledge.
Obviously, you need a wireless connection on your handheld to access the Wikipedia server. Unfortunately, it doesn't seem to be possible to fetch articles on the desktop and send them to your handheld for offline reading. Maybe in a future release?

Like the PalmAddict reviewer said, there are other ways to read Wikipedia on a handheld. But given the positive review, I am going to try it out myself.

Since my PDA doesn't have flat access to the Net all the time, without offline reading capabilities, this reader is useless to me.

Joshua of PalmAddicts also reviewed Quickipedia:

http://palmaddict.typepad.com/palmaddicts/2006/01/my_review_of_qu.html