Ag, the Silver Searcher, for Windows
Simply put, it's a great tool for searching through code projects or anything else on your computer from the command line.
Unfortunately, compiling it on Windows is a bit of a huge pain. I finally have it working on my Windows machine, though, so I thought I'd share it. Sources are the same as the Github repo, and it includes some DLLs from GnuWin32. It should work out of the box; put it somewhere in your PATH, and you'll be silver searching on good 'ole proprietary Windows.
You find download it over on my SkyDrive. If that link goes down, hit me up on Twitter (@Jaxbot).