Why not use a wiki? My fave is Wikka: http://wikkawiki.org/HomePage
The problem with a wiki, from my perspective, is the fact that it is unstructured. Some wiki's attempt to derive structure, or force users to use special syntax but that ends up being a little clunky. With structure comes some power. Tasks suddenly have meaning. A "Restaurant" data type can associate a map, or reviews. What we are trying to create is almost a personal content management system that helps users track all of that interesting structured data.
I am a fan of wiki's though. In fact I created
http://wikidpad.sourceforge.net/
Many moons ago.