Parsing Atom & RSS in Ruby/Rails?
If you meet crappy feeds, you may want to use HPricot to parse the feed.
Feedzirra is one of the better options: http://www.pauldix.net/2009/02/feedzirra-a-ruby-feed-library-built-for-speed.html
Of course, I'm biased since I wrote it. :)
Googleage reveals some things. Were they not acceptable?
Simple RSS
Ruby-Feedparser
require 'simple-rss'
require 'open-uri'
rss = SimpleRSS.parse open('http://slashdot.org/index.rdf')
rss.channel.title # => "Slashdot"