Linpedia - join
Linpedia.org is the original project created to further the knowledge of Linux/GNU via a community of devoted users. Linpedia.org will strive to be a medium for all users who want to post and share how-tos, tips, and general knowledge about Linux and other Open-Source Software.
Low activity, 16 members, moderated

Debian - join
a discussion group for anything about Debian GNU/Linux
Low activity, 283 members

Linux-Gentoo - join
This group is for discussions related to the Gentoo Distribution of Linux. Gentoo can be found at www.gentoo.org and is a very good but time consuming distro to utilize (at least in the beginning...stage 1 installer here :) ) All Gentoo enthusiasts and interested persons welcome.
Low activity, 172 members