Lately, I think about hybrid opportunities. There is no doubt that my MS in CS had a better bang for the buck than staying for a PhD. But now, I tend to be a "pure IT" software dev and rarely work on deep, interesting problems.
I sometimes think that doing a PhD to scratch that itch to work on deeper stuff, maybe publish in journals without the "or perish" mentality, and be someone who can lecture/mentor the next generation of hackers while still earning most of a living from hacking work rather than chasing grants all the time would be an interesting life.
HN'ers are an interesting bunch - are there hackers on around here (other than our own PG) who have a PhD, mainly work on startups and in industry, but also do some research or teaching in a university setting on the side?
Did any of that subset plan to do that (as opposed to getting a PhD, planning to hunt down tenure at a university, but wound up doing startups or industry work instead)?
I would strongly dispute any suggestion that a PhD is only useful for people who plan on staying in academia. I've found my doctoral experience to be very useful both while working on Tarsnap and while doing outside consulting; and in talking to other people in the startup ecosystem I've noticed a distinct difference in the quality and well-formedness of ideas coming from PhDs and PhD students compared to their less-educated colleagues.