- PCT Forum at TrailForums.com - Regular activity and generally useful and knowledgeable responses.
- PCT Forum at Whiteblaze.net - Regular activity; seems to have a bit more socializing.
- PCT Forum at Postholer.com - Sporadic activity; site also has lots of useful links and resources
- Forum at adventureonthepct.com - Lots of good info, but little activity since 2007/2008. Info spread over tons of categories.
I am a member at some of these (my username is RickD).
If you know of any more, let me know!