Two very handy resources when choosing forum software: opensourcecms.com lets you try out various installations – you can create test forums and play with the settings and forummatrix.org helps you compares applications on a variety of facets, and there's a wizard to help you narrow the choices.
Andy Powell makes the excellent point that social software-style tags function as virtual venues:
if you are holding an event, or thinking about holding an event… decide what tag you are going to use as soon as possible. … In fact, in a sense, the tag becomes the virtual venue for the event's digital legacy.
In other news, Intel get into Mashups for the Masses – "an extension to your existing web browser that allows you to easily augment the page that you are currently browsing with information from other websites. As you browse the web, the Mash Maker toolbar suggests Mashups that it can apply to the current page in order to make it more useful for you" and the BBC reports on Metaplace, a "free tool that allows anyone to create a [3D] virtual world" and incorporates lots of social web tools.