The Cruise Terminal is the furthest west dock. It is not possible to get to it by public transport. We took a taxi from the Old Port (Vieux Port) and it was 28 euros. A taxi from the main station (St Charles) is about 23 euros. Journey time about 25 mins.
Some cruises advertise Portofino as the port but they actually drop anchor in the bay off Santa Margherita and transfer you there by tender. Santa Margherita is nice enough for a wander around and has a small public beach immediately to the right of the pier where we swam in the sea after we returned from Portofino, just before we got our tender back to ship at 1730.
If you want to do Portofino without paying for an excursion though, turn right from the pier and you'll see a green kiosk beside the roundabout. You can either buy bus tickets from the counter or use the machine on the side of the building (which works in various languages). Buy 2 singles (out and return) for 1.20 euros each. The buses to Portofino leave from the stop at the kiosk -- Service 82. They run at odd times -- roughly every 40 mins - so check the timetable at the stop in Portofino when you arrive there to find out your return journey times. Expect the buses to be packed and you may not get a seat. Remember to validate your ticket in the machine on the bus when you board it. Journey time is 20 mins.
At Portofino, walk down to the harbour (5 mins). A nice tour is to walk to the right of the harbour, up a narrow street towards the Castle (signed Castello Brown). It's a nice walk with increasingly great views. Halfway is St George's Chapel but, about 50 metres before you get to it, the path branches off left towards the Castle (it is signed). Follow the path to the Castle. You can pay 5 euros for a tour of it (we didn't). We continued on the RED path (various paths marked through the grounds), which winds its way back down through the trees to a gate at the quayside and village centre (this gate is locked at 1800, by the way). About halfway down, you can take a diversion of about 20 metres to a bench, which is where the 'classic' photo of Portofino is taken from.
We left the ship about 1100, wandered around Santa Margherita, bussed to Portofino, walked around and snacked there, bussed back at 1525, beach and swim at Santa Margherita, ice cream and back on the tender at 1730. Easy day at a leisurely pace, which you could obviously extend if you get out your bed earlier!
The port isn't Rome : it's Civitavecchia. We left the ship at 0800 and didn't return till 1800. The coach trip to Rome was about an hour (Rome is a very congested city). We basically had a 'drive by' coach tour of all the sights so couldn't get off the coach, which was disappointing. The guide was excellent though (albeit he spoke French because it was a French tour). We eventually got off about 1130 and our guide took us on a short walk to the Trevi Fountain and gave us an hour to get some lunch. It was a sweltering 39 degrees that day! After that, a short walk and back on the coach to the Vatican City. Our tour included a 3 hour tour of the Vatican. It was terrible. It was incredibly busy. I'm not exaggerating when I say we felt we were on a conveyor belt -- sometimes you couldn't stop to admire the architecture/paintings/etc because of the crowds pushing you from behind. It was impossible to stop! Very unpleasant and a terrible shame as we know it is definitely a 'must see' but we reckon it is better to spend a full day in the Vatican in low or shoulder season to do the place justice.
A long, tiring day in scorching heat and felt we missed out on so much. We knew you couldn't do Rome justice in a day and will definitely go back for a long weekend. If you only have one day, I would recommend travelling on your own to Rome; all the major attractions are within reasonable walking/metro distance and will allow you a bit more time to appreciate them. Just forget the Vatican tour for another time (you can still visit St Peter's Basilica and Square for free as part of your own walkabout).
Our port was actually Salerno, an industrial port south of Naples. Doing anything on your own here still requires you to be bussed out as we were told you couldn't just walk out the port for security reasons. Our ship charged 8 euros to bus you to Salerno.
We did the Pompeii tour. We left the boat at 0900 and got back at 1400. The coach journey was fairly quick from Salerno, about 30-40 mins. Our guide took us on a 2 hour walking tour. It was great as a 'taster' but you could spend so much more time there. We would have liked a wee bit more time to wander around ourselves but it was still worth the visit.
The port was actually Trapani, on the extreme north-west tip of Sicily. We docked right next to the front street in Trapani and litearlly walked off the ship, through a gate and onto the pavement. Very easy!
We wanted to visit Erice without paying for the official tour. Erice is a beuatiful mediaeval town on top of the hill behind Trapani. There is a cable car from the east end of Trapani (5km from the port) which takes you to Erice.
We walked off the ship to the nearest bus stop (on sea side of road). Any bus takes you to the bus station. A ticket is 1.40 euros and can be used to make a second journey within 90mins. Buy your ticket as you board the bus. At the bus station, transfer to Service 23 (the 21 might do too) using the same ticket and ask the driver for the 'Stazione Funivia' (Cable Car Station). Get off the bus and walk left then turn right and you'll see the cable car station. A return cable car ticket is 6.50euros. Erice is beautiful -- plenty of places to eat, drink and buy souvenirs too. When you return, go back to the same bus stop for Service 23. It will take a tour round the north end of town, along the coast and bring you very close to the port (a bit to the east though). We just got off and walked to the ship instead of going back to the bus station for a connection. If all connections work well, you can leave the ship, take buses and cable car and be in Erice within the hour. Coming back, I would give yourself 1.5 hours just to be safe. Alternatively, just get a taxi to/from the cable car station.
Sailing in and out of Valletta is spectacular. The port facilities are good though you have a steep climb up to the town. I believe an elevator is due to open as I write (July 2012), linking the port with the gardens at the west end of the town centre, near the bus station.
A single day from a cruise ship is just not enough. The island is beautiful. We definitely want to have a holiday in Malta some day.
There are two tour companies doing open-top bus tours -- Malta Sightseeing and the more familiar City Sightseeing. Both do a variety of tours around the island on a hop on/hop off basis. We went with Malta Sightseeing (10 euros) for the North Island Tour. They said it took 2 hours with buses every 30 mins if you wanted to stop off anywhere. A bus every 30 mins is not enough to cope with the number of passengers and people were reluctant to get off, which made it difficult for people to get on. We witnessed a passenger revolt (nearly a punch up) when rival City Sightseeing passengers couldn't get on a bus in Mosta because it was already full. Realistically, you don't want to spend 2 hours on a bus ride across the island (it was actually 3 hours) or hang around for 30mins or more in the sun waiting for a bus when you've only got a day on the island. The tours actually leave Valletta immediately and so you don't see the town until the end of the tour.
I would suggest going straight to Medina/Rabat and having a wander around then return to Valletta for a wander about, either by tour bus or on the many Arriva local service buses, which leave from the bus station at the west end of Valletta. You'll get more out of your day and be able to spend some time in each of these beautiful towns rather than spending most of your day on an open-top tour of the island.