Code Snippets is a great little site that offers a online repository of code snippets. Anyone can register and post their favorite snippets. All code is tagged making the site really simple to use. There are currently only 29 users but I’m sure the idea will catch on.
I’m a big fan of Code search sites like Krugle and Google Code Search, but I often battle to find exactly what I’m looking for. The concept of tagging, the same as that used by GMail, is perfect and makes the process of finding exactly what you looking for really quick and simple.