If you have a Mac, upgrade to OS Tiger. That includes 'Spotlight' which has the fastest search engine in the world.

When you search via Spotlight, you’re actually accessing a comprehensive, constantly updated index that sees all the metadata inside supported files — the “what, when and who” of every piece of information saved on your Mac — including the kind of content, the author, edit history, format, size and many more details. And because Spotlight indexes content as well, your search results include what appears inside a file or document, not just its title.