If you've got an idea, start today. There's no better time than now to get going.
I believe photos is one of the underlying things in every social network that becomes successful.
Focusing on one thing and doing it really, really well can get you very far.
Great products sell themselves.
Every startup should address a real and demonstrated need in the world. If you build a solution to a problem lots of people have, it's so easy to sell your product to the world.