Just added a related posts section after the end of each post (here’s an example). For this functionality I’m going plugin-less and opt with this nifty code, which returns related posts based on tags....
Another great bookmark material.
Similar to 24 ways, but all about WordPress dev and hacks: WP Engineer’s Advent Calendar.
Smashing Magazine with another round-up.
Some of the code samples are gone, quite possibly due to WP’s text editor being its usual funky self, but otherwise an excellent resource.