Been asked a few time recently about RSS in WSS (I think one of the main reasons for confusion is the product comparison guide published by MSFT).
So, RSS in WSS, the consumption thereof. Is easy.
Simply add the XML webpart into your webpart zone, add the source URL to whatever you want (I was after Google news RRS) and then all you need a transform.
I am generally very lazy, so grabbed someone else's XSL:
Add this to the XSL Editor and you're done.
This isn't the best way of surfacing RSS in WSS, but it is probably the quickest...
EDIT: check this: http://www.sharepointrss.com/ (thanks Derek)