[kwlug-disc] Anyone know of a free web forum equivalent to Google/Yahoo Groups?

[unsolicited]

Anyone know of a free web forum equivalent to Google/Yahoo Groups?

Yahoo groups appears to have more functionality than Google, but 
neither appear to have the concept of 'sub-forum' (sub-groups?).

If it were K-W LUG, for example, then there might be forums for 
hardware, software, ubuntu, distros, general, mythtv, and so on and so 
forth.

Anyone have experience, ideas, suggestions?