So, for anyone else wondering, here's what I've got.
If you want to get the RSS feed for twitter search results, so you want the feed to register each new mention of a search term, you use this URL, http://search.twitter.com/search.rss?q=feminism but replace 'feminism' at the end with whatever search you want. Add that URL to your RSS reader, google reader, or whatever you use, and it should work.
The other thing I wanted was the RSS feed URLs for certain twitter accounts. These used to appear below the list of people the account was following, but not any more. Until you log out. So you have to log out, go to that person's account page, and the RSS feed link will be below the images of the people the account follows, in the right sidebar. Then, log back in and do whatever you were doing, but you have the feed URL now.
Hope that helps someone out! It's been frustrating.