Brainwave-guided interfaces are common. Most of the time, though, they're not what we'd call subtle. PLX Devices hopes to have that licked through the XWave Sport, a brain interface that disguises all its sensors through a fuzzy, exercise-friendly headband. Underneath the incredibly 1980s-retro (but washable!) look, you'll get about six hours per charge of tracking for concentration, relaxation and other noggin-related data that can transmit over Bluetooth to apps for Android, iOS or old-fashioned PCs. An SDK is available now, but pre-orders for the $100 XWave Sport won't ship until September 20th. That should give us enough time to perfect our Flashdance reenactments.