File this under the coolest use of C# ever...Clint Rutkas, rock star, built a homemade LED Disco Dance Floor (as seen on Digg) and recently he wrote a "how-to" article on Coding4Fun!! I seriously want to build one of these for my office in my "free" time :)
You should definitely check out the collection of YouTube videos and his party pictures to see it in action. The article is great and Clint manages to pull off a mix of Hanselman technical pragmatism, and Rory-esque humor which makes for an educational and entertaining read.
PS - I know the formatting needs to be fixed on the code samples