I've done a review on Face Unlock on ICS before, but Samsung added a face AND voice unlock feature in the security settings to make it a little more secure. In this video, I show you how to set it up and how it works. Honestly, from my experience while it is a little more secure than face unlock alone it isn't as secure as having a complex pin or password. But if you like face unlock than this is a good option. And I've got to admit, it is pretty cool!