I spend a lot of time thinking about this question, especially in the last few weeks as I was recently promoted and have to deal with more company politics than I really care for. In moments of exasperation I find myself staring off into the middle distance and contemplating what life could be like... I think I would travel more, read more, have more fun, cook, drink, run, play etc; the same thing everyone else would do if they suddenly found themselves with 40+ hours of free time BUT I would still need to DO something. The desire to leave a mark or to do something of note would leave me feeling frustrated if I didn't have an outlet for it. So I'd get heavily involved in open source software projects, something I already dabble in lightly but not as much as I would like. After that I'd love to volunteer my time to help fundraising for good causes like cancer research. I have kids and they have a safe, happy and healthy life, if I had to opportunity to adopt other children and give them the same I would.
Congrats on your recent promotion. I understand where you are coming from regarding your desire to leave a mark. I have the same desire. I have my children, whom I love dearly and I have no doubt that they'll do magnificent things, but I'm not ready to cash in my chips and claim them as my only legacy. I want to build something monumental. What? Hubski? A business? A work of art? All of the above? time will tell...