We loved Gibraltar but would have liked a little more time to explore everything. We went up the cable car to the top to admire the view which was fantastic. The monkeys (or are they apes?) were a little aggressive and snatched a couple of people's bags whilst we were there, so beware especially if carrying plastic bags as they associate this with food. The queue for the cable car was around 45 minutes but worth the wait, if you didn't want to wait there are plenty of cars/minibuses offering to take you to the top as well.
There were plenty of shops and bars and they will all take English money of course as well as Euros.
Barcelona was lovely and clean, P&O provided shuttle buses into town and we had a walk up Las Ramblas and back, the food market just off Las Ramblas about half way up is fantastic to walk round, don't miss it. Plenty of places to eat and drink.
For this full day tour the bus was waiting on the dock and we were greeted by a very friendly local chap who was our guide for the trip into Rome. The journey took about an hour and 30 minutes during which time our guide pointed out places of interest on the way. On arriving in Rome there was another guide who took us to see the Colloseum with a tour around the outside, we were given headsets to listen to what she was saying but these weren't very good so we missed some bits. Then on to St. Peter's Square where we were give free time of about 3 hours to do what we wanted the guide had suggested some possible things we would like to do in the time allotted and gave us a map to find our way round with the best and cheapest places to eat also.
We were a little disappointed to be confronted by street vendors and beggars everywhere we went some of whom were very persistent.