Brain wave meter knows what you're thinking, so get your mind out of the gutter (video)

A team from Keio University has built a brain scanner that knows when you're stressed, sleepy or interested. Resembling John McEnroe's headband, the device examines the frequency rather than the type of waves your noggin produces. That data, combined with the team's algorithm enables your thoughts and feelings to be examined in real time. Advertisers might want to use the tech to learn what holds our interests, but there's probably plenty of better uses we could think of -- you can come up with some yourself when you watch the footage after the break.