For those looking for a startup idea, here's a suggestion: Create a device which reminds one to stand up straight.
Having recently traveled to Haiti, I found the posture of the Haitian women incredible; though living in extreme poverty, Haiti's women had the poise of ballerinas. The cause seemed to be the large water buckets women of all ages balanced on their heads as they walked up and down the local mountains. Much like the books aristocrats used to balance on their heads in finishing school, the lesson of balancing a load on one's head seems to ingrain good posture.
The question is, can a device, say something that clips in one's hair and which communicates with a device in one's belt, perform the same task? Could it subtly send notification if one's posture is slipping? Perhaps it could vibrate like a phone, etc. I'm sure others here will have better ideas.
I'd love to own such a device.
I haven't tried one myself, although I am tempted as I often get quite bad back pain (at age 23 :-/ ), however I can't quite bring myself to add yet another device to my life that needs looking after, charging, etc.
However, I wonder if you can solve this problem purely with software. Could an app detect slouching by monitoring the user through the webcam?