Problogger points to this web site which allows you to gain some more stats from your Feedburner feed data. Averages, monthly trends and more. Don’t ask questions you don’t want to really know the answer to, though. You may not want to see that negative trend in your data. Use at your own risk! (SMILE)
Blog Perfume has put together an interesting blog tool that is designed to analyze the data that Feedburner provides publishers and to put it into a more useful (and pretty) format.
(Via ProBlogger Blog Tips.)