See the Pope by rita_simoes
You can't go to Rome and not see the Pope, at least that's what they say here in Portugal!The first time I went to Rome, it was August and the Pope had left to his summer residence, in Castel Gandolfo, so I didn't get the chance to see him.
Even though I'm not a very religious person, being at Saint Peter's square and entering the basilica does make me feel something. And so did seeing the Pope at the sunday Angelus, and all the people gathered in the square.
It happens at noon, every Sunday (except when he is in Castel Gandolfo) and there are big screens focusing the tiny window where he stands. Don't get there too late, though - it lasts only about 10 minutes.
The other possibility, which I didn't have time to do yet, is to attend the mess during the week - but you need to get the tickets before.