Keep cashing out until you have enough BTC to fund your start-up, don't act as if you had a million dollars, because you still don't have them.
It's hard not to have ideas for startups based on Bitcoins honestly.
You may be interested in putting some of the money you are making into ensuring Bitcoin is a success. For example, at the moment I think that MtGox predominance in the market is a bad thing for the future of Bitcoin.
Also, don't give BTC to people who just ask for them, like me: 1BNbVQBhfb8G4yG81bbcXWQmt7uDLrVrk3