Adding messaging board

It depends on what your host allows. Some hosts (most free ones, for example) don't allow the necessary things for message boards - databases and custom scripts.
http://www.bravenet.com has a lot of real nice free tools, including a very customizable message board. Also, http://www.ezboard.com is a nice site. Still free, may be charging a small fee in the future. You have to put up with ads for the free stuff, but if your web host doesn't have a message board already (many do - ask) and they don't allow custom scripts and databases (which won't be free anyway), you may want to check into it.
There are a ton of message board scripts out there. Find out what your host allows, what OS they use (NT/Unix) and what languages they support before trying any of the stuff you find.

See below links (remove spaces) for a ton of matches.
http://www.google.com/search?hl=en&q=message+board

http://www.google.com/search?hl=en&q=message+board+scripts

HTH
Nikki

My friend uses XForum 1.5B0 by Trollix Software (http://www.trollix.com) original script by xmb (http://www.xmbforum.com) on his website.

It seems alright, the only thing is its PHP
HTH
Fred