In many ways this is a fabulous movie--complex, warm, chilling, even poignant. It's meant to be an almost serious look at contemporary relationships, including sexual ones with prostitutes, affairs with fellow workers, quickies with someone new, and long term loves between married husband and wife. It works overall, sometimes really well.
Because of its seriousness you might notice a few scenes where things are pushed a little hard. The main one of these is when a Brazilian girl comes on hard to a recently released sex offender in an airport after moments before being put off by him and having plans to meet someone else for a polite drink. At first it's improbable, then the writers decide to push the encounter harder and harder until it becomes extreme and sensationalist. Too bad, because in other parts of the movie the extremes--such as a prostitute getting started through sleazy photographer listing her on the web, even though she has zero experience--get pulled off with conviction. Not that most of us know the ins and outs of that world.
There are too many characters to make things clear here, but it's worth saying that Anthony Hopkins again shows how he can command a scene like no one else in the film. His monologue at an AA meeting is a short masterpiece, and his performance in general is almost enough to justify seeing the film all by itself.
Other characters are excellent, including Jude Law in a restrained part as a married businessman looking for some action on the road. (His wife has her own affair in full swing.) Yeah, come to think of it, there is a lot of infidelity going on here. The one sincere relationship is another unlikely moment, with a sweet girl going off with a somewhat mixed up Russian in a Mercedes (and she leaves her bag on her park bench for no good reason, she's not in a hurry). But hey, all of these things are happening so rapidly and with so much overlap, who knows? It even includes many cases of split screens reaching three or four simultaneous panels at times.
You start to see how the world works for some people in a contemporary way. It's sordid on some level, filled with deceit and sadness. But it's also believable, at least for this certain urban, footloose set. I assume the title means that it all comes around full circle somehow, that we're all in the same big boat. Watch with attention. The characters are all distinctive but there are a lot of them. The director, Fernando Meirelles, is ambitious, for sure, but he made of the most highly regarded films of recent years, "City of God," so this is worth watching even just for that connection. "360" is limited and flawed by comparison, but it's better (I think) than its rating might let on.