I think Fodor's has the best travel forum around. Can anyone recommend other good travel forums?

Tripadvisor is not bad.........but, not as good as this one. They do have a couple of good members.

Not as good and I've tried most of them, I think.

I think it depends which country you're interested in. Trip Advisor is much more active for Morocco - but is not as hot on the rest of Africa. Lonely Planet Thorntree is also extremely active for almost any destination - it appeals to the more independent traveller, i.e. not so many people discussing tour companies, hiring professional guides, or higher-end accommodation.

Forgot to mention Virtual Tourist!

travelerstogo.com is another good forum, though the Africa board does need new members and input. The Europe/U.S. boards are hopping, a fun, nice place to spend some time.
safaritalk.net has some very interesting interviews. not exactly a forum per se, but a place to learn, post trip reports, photos etc.