I finally found a good RSS reader for my Pocket PC. It's RSS Sync.
I love it because it's much faster than using AvantGo (when syncing). But, unlike AvantGo, the entries are truncated. I wish I had control over that one aspect, since the reason I use a pocket pc tool is to read offline and it's not possible to follow a link to the website. The advantage over AvantGo is that you get just the content.
It requires Windows Mobile 2003 and Activesync 3.7.