MSN Desktop search (or other search engine) is definitely the new must-have tool for developers, specially if you work with a laaaaaaarge code base. The title is self-explaining:

•  install MSN Desktop search,
• set up the indexing to point the source code folders
• wait a few hours for indexing depending on the size of your project
• pick any class or method and write it in the search bar...

The results are just lovely! It is easy to browse, relevant and fast!