I'm enjoying my Dell Axim x30. I've ended up using primarily as an ebook reader, email reader, and web browser. Before I bought my Axim, I had tried to browse the web on an older ipaq. There is no contest. If you want to use the web, you need Windows Mobile 2003 second edition. Pocket Internet Explorer has some really nice wireless features, like you can tell it to put all of a web page's content in one column, very nice (although this does mess up some sites' style sheets).
Since most of the sites I check frequently are blogs, or blog-like, I love RSS on my Axim. RSS allows me to find out when there is new content, instead of me having to wait forever for the entire page to load, then find out nothing is new. The program I use is called qmail (this is a free Japanese program), but there is an how-to in English. It's a pain to set up, but once it is set up, it's great.
The ebook reader I use is Vade Mecum. It's an open source Plucker clone for the Pocket PC. I like Vade Mecum because I had a bunch of ebooks in plucker format from my Clie days. It also supports highlighting and annotating. It can be a little slow though. Fine for just reading, but a pain if you are trying to keep up in a larger document in a class and have to jump around in the document a lot.