Since I see a lot of people asking and wondering about free hosts, I decided to start a thread. All the free forum hosts that I find will be listed in here, but others are free to contribute their own findings. Unless I state otherwise, I cannot ensure the quality or reliability of these services. Most of them should be good, but please bring to my attention any and all problems you have.
PHPBB:
Boardster.net Free Forum Hosting
http://www.freemyforum.com/
FreePowerBoards - Free phpBB3 Hosting
#1 Free Forum Hosting - FreeForums.org
MakeForum.org - Free Forum Hosting
Free Forum Hosting - Free phpBB Forums Hosting
PHPBB&Invision Power Board
Free Forum Hosting: phpBB and IPB
Free InvisionBoard and phpBB Forum Hosting