I can understand you want to get the most from a short trip to another continent, but Rio really does have quite enough to keep you busy for the days before the party starts. And I'm not talking beaches alone, there's loads to see and do. Any guide-book will fill you in.

But if you must move around, of those places mentioned, Buzios is pretty enough, in a chic-smart sort of way. Petropolis is a nice drive out from Rio into the mountains, but apart from a couple of bright spots (e.g. the Imperial Palace) much of the place is a dump for cheap clothes shopping. Parati is like Buzios but with edge, some cultutral pretensions and altogether more charm.

All these places will be heaving at the time you plan to visit.