Santa Teresa -The best view of the Best Rio
Take the tram at city center (lapa), don't be afraid - a lot of tourists do the same. Use a regular digital camera (don't be afraid doesn't mean "abuse" your security).
Ask how to go to Paineiras!
From there you can see most of the beautifull sites that you dream in Rio: The Christ, The Sugar Loaf, Copacabana, the Rio-Niteroi Bridge.
You can also make a helicopter trip from there.
At Santa Teresa itself there is a lot of artist's galeries and some ineteresting buildings.