Anyone know where I could find a good free reliable message board that is also already hosted (much like this one)?

My Ikonboard (http://www.myikonboard.com/intro.php)

They have a free package with limitations that is fairly decent:

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Because it is FREE you will have to deal with ONE small banner and you will only have one default skin for your board, but we have other affordable packages for you to choose from and upgrade as your community grows.
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InvisionFree (http://www.invisionfree.com)

Free Invision Power Board hosting.
Although they have some problems from time to time, lots of people still use them, so they must be doing something right...