Well, the one I linked is under a CC license, so that's a big plus IMHO. It stores in flat files too, so it should be a piece of cake to set up.
As for what others use, I notice most people use a "hosted" shoutbox thing that links to storage/code elsewhere. I've seen several of those break for me because I use ad block, and they keep trying to sneak ads in or set cookies for a different site, which is a security no-no for me.