Bloglines/3.1 (http://www.bloglines.com; 4317 subscriber)
it will add 4317 subscribers to your feed. If you had 100 readers, now you have 4417. Cool, uh?
We realized a web app to “boost your feed readers” just for fun and to show how it works. You can find it here: Tessarolizr. Just add the last part of your FeedBurner feed (that after http://feeds.feedburner.com/) and the number of readers you want to add and click “Tessarolizzami!”.
UPDATE (10/08/2007): it seems that the bug has been solved (at least for now), as promised by Dick Costolo (FeedBurner). Mission accomplished. :)