There are lots of things that put a smile on our face.

David Beckham in an Armani underwear ad.

Designer gear that we can actually afford.

And, if all else fails, a motor-powered metal spike that beans us in the skull until we flash those pearly whites. Ouch!

That's just what inventor Lauren McCarthy's Happiness Hat does.

At first glance, the hat looks like any other white wooly winter topper. But according to McCarthy's site, the hat features a headpiece-like bend sensor that hangs by the cheek and measures the size of your smile -- or lack thereof, as it were.

If the little guy decides that you're not meeting your perky potential, it sends a signal to a servo motor which will then direct a metal spike to strike you on the head, inversely proportional to the degree of smile, McCarthy says.

McCarthy explains that over time your brain will be conditioned into smiling continuously.

No kidding -- we'd be grinning from ear-to-ear if it meant avoiding a jab to the noggin.

happiness hat from Lauren McCarthy on Vimeo.

McCarthy describes smiling to StyleList as "a simple action that has the power to make you and everyone around you feel better."

Adding, "I am interested in the way we interact, how the individual fits into society, the patterns and expectations of everyday social behavior, how these can be questioned and rethought, and the underlying psychology/neuroscience of it all."

"Though not entirely practical, this piece is a call for all of us to take time to think about these things, see the systems and frameworks we act within, and explore alternatives," McCarthy told us.

And if nothing else, it would make one killer Christmas present for that pouty Victoria Beckham.

These wacky hats also make us smile... sans the pain.