Mark Pilgrim has released a new version of his Universal Feed Parser. I have mixed feelings about the long term viability of this code, since it parses feeds which do not meet the specifications, which ultimately means that people never fix their broken feeds, but the specification itself is wooly enough that this is perhaps unavoidable. In any case, I’ve used it before, it works, and he seems to have done a lot of work generating test cases for it. Give it a try.