I had to do a wordpress password reset for a user today. When I googled how to do this (from the raw database), I got these instructions.
Really cleanly, clearly, well-written.
...except they don't work.
Recently, Wordpress decided to implement their OWN password hashing algorithm. Which means that while it's less immune to rainbow tables of plain MD5, it means ALL this documentation is shot and doesn't work anymore.
Yay for letting your community write your documentation for you.