I know term Web 2.0 is way over-hyped and way over-loaded, but I recently got pressed by an ISV asking about how MOSS supports Web 2.0 type functionality. When I asked for clarification, I was told "you know, blogs and wikis and communities and ratings and things like that." I replied with my best Ralph Kramden Chef-of-the-Future impersonation, which needless to say didn't go over very well (but it did reasonable job at evoking pathos, which got me out of the room intact.)
Left to my own devices, I did what any reasonable softie would and begged for the help of someone much wiser and much more knowledgeable than me (disguised as a "can you believe this request?" email.)
My colleagues immediately saw through that, but also took pity on me and pointed me to the Community Kit for SharePoint up on Codeplex ("you have heard of Codeplex, right?") While some of the features I mentioned above are in the base MOSS offering, the Community Kit really propels this up into the rarefied air of Web 2.0-pia (or so I'm told.)
My takeaways from all this are to let others define what Web 2.0 means to them before volunteering an answer, to keep a closer eye on Codeplex when looking for enhancements to the Microsoft stack, and to never underestimate the power of pathos when you don't have a clue what to do or where to turn.