Courtney just clued me in to the existence of Greplin - a service touting itself as "the search bar for your life." The short of it is that it connects to a bunch of different API's - Gmail, Twitter, Facebook, Google Docs, Evernote, Dropbox, etc - and allows you to live search all of them simultaneously. This is, obviously, a phenomenal tool to have around and they've actually done a great job of implementing it. Your search can index can only get so big before you'd need to upgrade and start paying them a monthly fee but, for the meantime, it's well worth trying out.