What sector do GOOGLE or TWITTER belong to after all? The late Peter Druker once commented that most of the interesting work would be in the social sector, as that is where the unresolved problems rest. I wonder if he fully anticipated how non-profits are not the only enterprises focused on social issues. Many for-profit companies are headed there as well. Google is enabling educational advances in very poor areas and we all witnessed how Twitter gave voice to Iranian protesters. Donna Fenn, best selling author of Alpha Dogs and Upstarts and contributing writer for Inc. comments that business start-ups among young leaders is at all time high with Generation Y. And most of these, she shared at the recent Wisconsin Early Stage Symposium, are involved in social entrepreneurship in some way. HP and P&G are among the many Fortune 500 companies that…