I spent a week there last fall and had an amazing time. I went alone because no one else from here would go with me, and I was so nervous about the risks that a co-worker had to give me a Xanex a few hours before my flight departed! I stayed in Ipanema and walked everywhere, even at night. There is a strong police presence on the streets, very few homeless compared to US cities, and almost every apartment building had an armed doorman on the sidewalk. I only carried about the equivalent of US$40 on me at a time, and only one credit card. The other money and cards I kept locked up at my hotel. Shorts and a t-shirt is the unofficial daytime uniform, so wear that to blend in a little. Night time is a little dressier, and dinner really isn't taken until around 9pm. Use street smarts, and if at night, take cabs, which are cheap and for me, always honest, or stick to walking on main, populated streets. I had only one bad incident, one evening i went out on the rocks at Aporador to take some sunset shots and two teens asked me what time it was. I told them in my halting portuguese and pointed to my watch. Not a minute later i heard them ask a French couple behind me the same question. I figured they were looking for watches to steal, and my citizen didn't make the grade, but I got my photo and got the hell outta there! By the way, much of the time I carried disposable cameras, as these don't attract attention like a Nikon would.