Okay, so I'm still trying to figure out how to get an RSS feed to work on my free Blogger/Blog*Spot blog. I did sign up for the BlogMatrix RSS feed generator, but about one day later (and I don't thing there's a connection), the BlogMatrix box crashed. So until that's back up, the feed is not going to work.
After digging around, I found Blog Bloke's very clever way to manually generate an RSS feed that works with Blogger/Blog*Spot so long as you have some spare webspace to host the RSS file. It probably would work for me, but at this point I'm not feeling too pressed to have an RSS feed. (Plus, I'm hoping BlogMatrix will come back up one day soon.) That said, it is an ingenious solution, well worth considering for those who absolutely have to have an RSS feed for a Blogger/Blog*Spot blog and need it now.