Serendipitously fell into it...
Instagram, Pinterest, Square, Ayloo.net, Counterless
Building a great, polished product is definitely the most frustrating and rewarding part of being an entrepreneur.
Focusing too much on networking, instead of building an awesome product/company.
1. An idea alone isn't worth much.
2. Someone has or is already trying to do what you're doing. (You're not a unique snowflake)
3. You don't have to be in San Francisco.