We had a day and a half in Rome before our cruise departed from Civitavecchia. We were also staying in Rome two days after our cruise, but we actually saw everything in the day and a half before the cruise. One our first day, we saw Campo di Fiore, Piazza Navona, Pantheon, toured the Collesseum, walked through the Forum, (napped), saw the Trevi Fountain and the Spanish Steps in the evening before sunset. The next day we got up early and were expecting to meet an English speaking tour group at 7:45 am at the metro stop by St. Peter's. They didn't show and we thought we wouldn't be able to get in, with the line being so long. We were walking around to get in line, and someone approached us and asked if we wanted an English speaking tour, and said that as soon as they opened the doors at 8:30am it would take 5 minutes to get inside, so we said yes. It turned out to be fantastic. You have to have a guided tour of the Vatican museum - there is so much to see, it's like they have every single artifact of the Roman Empire. Puts the Smithsonian to shame (I am from DC). We did the tour in 3 hours and made it back in time to our hotel to check out at noon and head to the coast for our cruise. Good luck!