I don't know if the following situation is common among you, but at my place it happens pretty much with some annoying cousins.

When you're playing and you have to interrupt to do whatever you have to do, you pause the game, and when you get back someone else is playing. Your son is accidentally buying stuff on marketplace. Your dog is playing. Screwing your points. Deleting your progress.

Now imagine a Natal app running in the background, constantly scanning your face. When you leave, the console pauses. When you get back in front of the camera it continues.

If someone else tries to get the machine working, they won't be able because the facial scan will fail.

This app could be used for system startup also. Only you could boot up the console. Also simple gestures would be shortcuts to menus, wave your hand to open the disc tray without browsing the menu for example.

All this while playing regularly on the system.

Do you think is would be useful at a fair price? Or even be standart with it maybe?

Might work with voice recognition, too. You would probably want to use whichever is more reliable between face and voice, or perhaps a combination of the two.

I think it would need to be integrated into the console OS. Could be really useful for parental controls, too. Sorry Timmy, your profile has not been authorized to load M-rated content.

Or can't you just use a simple password system?

Excellent idea! This type of thing, along with RTS games and the old Minority Report dashboard are where Natal will really do well. Oh, and a Myst remake!

@ famousringo

But voice recognition while useful feels much more awkward to do instead of a gentle hand movement, that feels pretty high tech imo.

@ akvod

Password system requires you to input the password and someone might discover it.
Facial recognition, while just taking a little time to do, no one can fake or get through that security system. Unless you have a twin brother.

Or hold up a life sized photo of the person face up to the camera.
I like the idea. sounds good.

"What are you doing Dave?"

Or put the control where your kids can't reach it.

It's a 3D camera.

"Hey, I thought you said that plaster cast of my head was for the wax museum!"

The costs of facial recognition don't seem to justify the relative ease of creating a unique and hard password. Don't choose your dog's name, but a series of numbers or add some weird symbols at the end of nonsensical phrases.