Wiki wiki patterns
Paraphrasing the Enterprise Solution Patterns Using Microsoft .NET book, most complex systems are built by composing (and composing, and composing) simple, proven solutions. And of course, a programming pattern is a simple, proven mechanism that solves a small problem effectively. Hence the popularity of design and programming patterns. On the other hand, the wiki wiki web is a very effective tool for a community to build reference encyclopedias. Thus, it sounds like a great idea to have a patterns wiki. Come to think of it, there must be a handful already, but what caught my attention is a wiki specialized in patterns revolving around .NET: http://patternshare.org. A place worth watching, not only because its renowned authors but because we can also actively contribute.