There seem to be a number of solutions out there to help you deliver SharePoint content via RSS, thought I would just put togther a quick summary (in no particular order!):

1. Maurice Prathers Web Part:
2. Addy Santos BlogWave:
3. George DataView and XSLT (via Bill Simser):
4. U2U are working on something according to Jan Tielens:
5. DevHawk SharePoint Syndication:

Now, folks, I know I have forgotten some, my apologies in advance…Tell me about it and I’ll update the list.