This Saturday there is going to be the first “WordPress Bug Hunt”. The aim of the event is to blast through all the outstanding bugs in Trac marking fixed those already fixed and working on developing fixes for those that still exist.
Skippy recommends that you bring along a text editor and a fresh install of WordPress 1.6-ALPHA-2-still-dont-use a good way to do this is to setup a local install on your home computer for example using XAMPP if you are running Windows or using these instructions if you are on Mac OS X – It both cases don’t forget you want to install the latest svn version.
There is a dedicated IRC channel for people to meet up on on the day and discuss the bugs which is #wordpress-bugs on freenode.
You don’t need any coding skills or experience to turn up. Just being willing to attempt to test whether or not bugs still exist will make you very useful as some of the open issues date from v1.2 and earlier and have quite likely already been fixed.
Update: There is now a dedicated codex page for info about the WordPress Bug Hunt(s)