• Laptop theft is common, so keep yours hidden and carry it in an ordinary bag not a laptop bag.
• Keep your wits about you from the moment you get off the plane, as many scams and robberies begin at the airport. One involves a well-dressed official looking man who claims to be a police officer escorting tourists outside of the airport and then pushing them into a car and robbing them. Another involves a scout identifying cashed up tourists as they get into taxis, then phoning ahead to their friends on motorbikes who rob the cars once they're out on the road.
• The favelas (the slum-like suburbs in Rio's hills) are home to gun-toting organised gangs, so be very careful where you wander. That said, the favelas are not to be avoided all together and can be a great place to meet real locals and take in the best views of the city. To visit the favelas safely, it's best to join a tour group or at the very least ask a trusted local for advice on where to go.
• Despite Brazil's high crime rate the good news is that during the Olympics authorities will be doing everything they can to prevent incidents that could bring Rio bad publicity while the whole world is watching.
• As a tourist, expect to be charged higher prices by street vendors and to sometimes be taken the long way around by taxi drivers. This doesn't mean that everyone is out to get you, but it would be against the 'Brazilian way' ('jeitinho brasileiro') to pass up the opportunity to make an extra buck.
• Bank card skimming and credit card fraud is a risk in Brazil as it is in most countries. Cover the keypad with your hand as you enter your pin, never let your credit card out of your sight, use cash where possible, and let your bank know if you notice any unexplained transactions on your statement.
• Be careful using free Wi-Fi hotspots and avoid doing internet banking on untrusted connections.

For more information see the Brazil laws and culture guide.