I've also played with Magpie RSS parser and so far it looks great. One thing that amazed me was that it deals with atom feeds as well as RSS without you having to specify which. I have regularly been using hosted RSS feed services on my site
http://www.fivesandwiches.com from people like Blogstreet and Feedroll, the trouble is that I wake up one morning and find that my pages are grinding to a halt because one or other of the feed services is down. I am in the process of using Magpie to create my own hosted/cached feed service at
http://www.blogfuel.com where I already have a tool for inserting amazon xml content. My favourite trick with RSS/atom feeds is to use them to 'advertise' my own pages within my sites. Most of my sites have a blogger driven weblog at the front and I can put highlights from these using RSS on pages deeper in the site to get the user back to the page I want them to see most.