Further Update:
Due to an excessive amount of spam (just look at the recent changes page if you don't believe me), I have now disabled anonymous editing and username / password registration. However, you can still use an OpenID to create an account.
Update: Now with OpenID support!
There was quite a bit of discussion on this question in regards to the so-called dev-tip questions / posts here. Being the type of person who wants to step in and help in times of confusion (confusion being the lack of proper facilities for handling these questions), I decided to create something myself.
So here goes...
I downloaded, installed, and configured MediaWiki on my server. The idea is you can post ANY valuable API related tips / advice there.
Here's the link:
http://stackoverflow.quickmediasolutions.com/wiki/
Enjoy!
Note: Please don't forget to sign up before posting... it helps me know how the site is being used / its popularity / etc.