When I was building ChrisKenst.com I wanted a way to add the recent feeds from my two blog sites (including this one). I couldn't remember the previous site I used but I remember the wizard was customizeable. I did a quick search and that's when I found Google AJAX Feed API.
All you do is go to the Dynamic Feed Control Wizard click the Start with Wizard link, enter the name of your blog or website with the rss feeds you want and Google with find the exact URLs for you. Lastly click the Generate Code button and copy and paste the code into your website.
Looks like Google has a number of cool AJAX API's in Google Code that might be worth checking out.