http://esljokes.net/index.htmlThis site contains jokes based on useful grammar points in English. Each joke is followed by a grammar explanation and exercises on the grammar and key vocabulary from the jokes.
This site is currently being updated and when it's completed there will be more than 70 jokes. (If you don't see any changes, click the "refresh" button on your browser.) I plan to build this site into the number one (and possibly only) collection of jokes for ESL on the internet.