I've watched a few of the Instagrams and dang if he doesn't hit his mark each and every time. I tend to think there is some kind of editing going on, probably in camera but I gotta say it is a slick executions of using the limitations as an advantage.
Mashable has a post on how to create Instagram Videos in 7 Steps. You can also review the Instagram Help page; a little dry but you might find what you need.
Other Posts of Interest
- Audio Recording Tips for Mobile Devices
- Clocking the Words in Time
- Animoto for Android Video Creation Tools
- Home Page for Mobile Users