(Image credit: Nymi)

The Nymi wristband takes password protection to a very personal level: your heartbeat. Heartbeats are unique like fingerprints, but don't leave traces behind. While the wristband, available later this year, can be used with anything that's password-protected, they hope to eventually build gestures into the device so that it can unlock your car as well.

Unlock Your Car Or Computer With This Heartbeat-Tracking Wristband | Co.Exist