A few months ago I became a Ruby On Rails developer, and although the documentation isn't bad, I often have need for lots of snippets of code, and developed Snippets to hold them. However, anyone can use it.. that's the whole point :) It uses the tagging/folksonomy that's typical to many sites these days. You can narrow down code snippets by tag, so you can first look at all the ruby code, then ruby + rails, then ruby + rails + authentication.. and so on. Makes it easy to find exactly what you want. You can also steer clear of everyone else, and simply look at your own code snippets only, and narrow down with tags on those too. Powerful stuff. Best part? Thanks to Ruby On Rails, 28 hours after coming up with the idea.. here we are. Yes. It took less than 2 days of coding. I love Ruby on Rails (and that's hard to say, being a die-hard Perl monger..)
You database wizards might also appreciate this article about how I did the tag intersections in a single SQL command without endless joins. It took some work, but we got there in the end.