If my mother is to be believed, this is how I've looked over the course of my life (whoa, can I blame my belly pooch on this? Maybe it's only a bad posture-induced optical illusion!). She was always especially quick to point it out if I had to appear on stage, for a choral concert, or a school musical, or that time I emceed the honor society awards because I'm a huge dork. "Now, remember to stand up straight," she would tell me, to which I would roll my eyes, because that is my response to everything, even now.
Perhaps the iPosture would have solved everything!

"The iPosture is an intelligent electronic device designed by physicians
and engineers specifically to improve posture. Small, discreet, and
designed to be worn close to the skin, it sends small vibrations to
alert the user when one's posture is not ideal."
I don't know about you guys, but I'm horrified by the very concept of this torture device. If you really want one, though, they'll be available soon.
[$99.95, iPosture]
[Via Crave]
Related: Cheap Trick: The Disembodied Voice of My Mother