Don't let people tell you your ideas won't work. If you're passionate about an idea that's stuck in your head, find a way to build it so you can prove to yourself that it doesn't work.

Stop sketching and start building.

I keep a notebook in my pocket, and I write down all the stuff we could ever do with Foursquare.

Forget about where you want to be and go out and build stuff. Dodgeball came from being bored at work... things happen because you make them happen. Stop sketching, and start building.

Don't let people tell you your ideas won't work.

Do what you love and the rest will come.

I used to snowboard 30 days a year. Now its down to eight.