The guys at Creative Nerds have amassed the most massive collection of cool RSS feed icons on the web--over 1,500. The best part is they are all free to use on your own blog or website.
There are RSS icons with flames and ones shaped like panda bears, hot air balloons, coffee cups, and shopping bags. I have to say though, my favorite is the hip fedora hat with the feed icon slyly tucked inside the banding.
Images 1, 2, 3, 4, 5, 6, 7, 8, 9, 10