I am flying to Rio at the end of June and will be connecting through Sao Paolo where I will be from 9 am to 6 pm. Is there enough to do in the city to warrant leaving the airport? I've heard about the crime and am thinking about signing up for a guided tour of the city. Can you recommend any guides/agencies that provide that kind of service? Any other tips on Sao Paolo and Rio are appreciated - will be my first time in Brazil. Obregada!