From someone married to a PhD, I suggest the Google route. With the PhD you'll likely be more distanced from what truly interests you (the topic is essentially

From someone married to a PhD, I suggest the Google route. With the PhD you'll likely be more distanced from what truly interests you (the topic is essentially a negotiation between you and faculty) and what may continue to be relevant in the coming years. It will also turn into quite a slog by the end of it, as it's almost designed intentionally to put you through the wringer. Many people come out being disillusioned. This may vary with your chosen college / subject area though. Taking a job at Google would expose you to the right type of environment, with lots of internal opportunities. It would also look great on your CV and be a springboard to other opportunities outside GOOG. The startup thing could work, assuming you have the right combination of skills, business idea, commitment to make it happen, and know a few others who could join forces. Bit more risk with this one, but obviously a bigger payoff.