I've recommended Nick Corcodilos' Ask the Headhunter web site before for its unorthodox, yet sensible, advice to finding the best job for you. I'd recommend that you sign up for his newsletter on the web site if you like what you see. This week, he describes taking a Library Vacation(tm) for someone contemplating a career (not just job) change. It's an exciting idea!
I've seen a few friends leaving the high-tech industry, and their transition plans sometimes could use more rigor. It seems like everyone wants to get into a "green" or "alternative energy" job! I'm sure that will be big eventually, but it's better to expand your search space, and carefully consider what you would be passionate doing.