http://www.beseen.com has a free message board available for use, just add a link to it.

http://www.ultimatebb.com has a message board, but it costs $170, and it isnt very good,
http://www.vbulletin.com has a VERY VERY VERY GOOD bulletin board, which also costs $170,
http://www.bravenet.com has a free message board..


and I am sure you can find other free message boards by using a search engine.