A few weeks ago I was on a panel discussion at Cyberposium 2005. The panel's moderator was Ken Morse, a lecturer and managing director of the MIT Entrepreneurship Center. Professor Morse has quite a lot of experience with startups in the technology industry (having been involved in launching companies like 3COM, Aspen, and others) and is also a founder of the MIT center.
In the closing of our panel Professor Morse offered some words of advice to the attendees (mostly students graduating from business school at Harvard and Sloan). I think the advice was worth repeating as it is equally appropriate for those pursuing careers on the technical side of product development. He suggested two key things (my paraphrase from memory):
Just wanted to pass that along. I joined Microsoft because I wanted to learn how to make the things we were talking about in graduate school--make things for millions of people (you can read that in the recruiting brochure from 1990!) The one thing that has changed the most is that we make things for hundreds of millions of people now.