There are a ton of startup incubator programs and investor lists and VC blogs and tech meetups out there that could connect you with mentors and advisors.

If you think a 5 minute conversation with PG is going to dramatically affect the success or failure of your venture, I think you might want to broaden your search - there are plenty of other resources out there for new entrepreneurs. You should probably be looking to talk to anyone out there who will listen to you about your idea -- PG is just one guy.