I seem to have forgot to post about this app, but it is one I use often and it is free! Hey, how can you beat that?
There are many file search programs out there and you have Google desktop search and even Vista comes with a file search ability built in, but I still end up falling back on this useful utility program. I know it is not specifically a development tool, but it is handy when you need to search files beyond the simple Find in Files options of Visual Studio.
The product is called Agent Ransack from Mythicsoft Ltd and they release it for free. They have a more advanced product available for purchase. When you visit their site, but sure to check around at other free and commercial products they have available. Here is the link to Agent Ransack:
http://www.mythicsoft.com/agentransack/
Agent Ransack allows you to search entire drives or sections for both file name pattern and contents. It then lists all the matches and when you click on them, will show a brief clip from the file for the matching content. Is really handy since you can search and then browse the results seeing the matching content without opening the files. You can even right click on the matching files and bring up it's properties or open the location or launch the file itself.
Searching methods include standard text or regular expression patterns.
Be sure to give it a look, I have used it for years!