Google Code Search

Recently I  found Google Code Search (via Labs) and its pretty amazing!
If you usually "google" for some code you end up on some blog, forum, mailing list or such. But It seems there are some (open source!)  repository's connected to GCS  and this is interesting because it allow you to look for specific API's or usage of the same. I was looking for some advanced JFace Viewer examples which provided custom column editing. The user interface of GCS is really nice and let you explore e.g. a complete SVN repository so you can find the you file with your desired snippet. Additionally it enables you  to see how the class containing your snippet is actually used with other classes.
In my opinion GCS is a very powerful tool which enables you to search for code from a very different perspective.