It’s easy, if you know how. And thanks to the blog, Stay N’ Alive, I know (and now you do too):
Currently the only way to find an RSS feed is to log out and visit the profile of the user when you’re not logged into Twitter. This might also be why Google Reader still recognizes feeds when you enter user profile URLs in the “Add Subscription” box. Firefox doesn’t recognize the feed when I’m logged in – it does when I’m not. It does make you wonder how long the RSS feed will be in the unauthenticated version.
(I added the bold and the italics. )
There’s no way to guess it, since the feed has a numeric id in it that doesn’t relate back to the person’s twitter handle.
I hope they keep the RSS feed: I like processing that feed in other blogs, etc.
Smart People I Know 