If you like to get some humor on your site, i've created this feed that is updated twice a day. No ads on it, just the first 20+ words of the joke, they have to click the link to read the rest on our site ...
http://www.maddaisy.com/rss/fun.xml
If you want to use if but don't know how to implement it I can help.
Here's an example:
http://www.maddaisy.com/rss/rss.php
You can have any number < 10 on there if you want though.