You think you know the Rewrite API (http://codex.wordpress.org/Rewrite_API)? Think again!
Rewrite rules turn request URIs (e.g. /2012/10/13/i-ate-an-apple/) into query arguments (e.g. year=2012&monthnum=10&day=13&name=i-ate-an-apple&page=) that WordPress can understand. The Rewrite API is close to, but not exactly, like turning lead into gold. And almost as powerful.
In this meetup, Daniel Bachhuber will take us through the ins and outs of the Rewrite API, as well as some common use-cases / pitfalls.