Going on a Mediterranean cruise...port ideas?

[JONNYROTTEN]

We're leaving for a cruise in a few days....getting pretty excited!
We got a hotel room for a couple days in Rome to give us time to see the city. The itinerary looks pretty awesome and the reason for choosing this cruise...not a single day at sea.
We have a good idea what we're doing some of the trip but looking for ideas for a few ports keeping in mind we're only at each place for one day.

Need ideas for:

Marseille France
Palma Majorca
Calgliari
Valletta Malta
Messina Sicily

Thu Rome (Civitavecchia), Italy --- 05:00 PM 0
Fri Florence/Pisa (Livorno), Italy 06:00 AM 07:00 PM 0
Sat Cannes, France 07:00 AM 07:00 PM 1
Sun Provence (Marseille), France 08:00 AM 06:00 PM 0
Mon Barcelona, Spain 07:00 AM 07:00 PM 1
Tue Palma, Majorca, Spain 08:00 AM 03:00 PM 0
Wed Cagliari, Sardinia 10:00 AM 06:00 PM 1
Thu Valletta, Malta 01:00 PM 09:00
Fri Messina (Sicily), Italy 08:00 AM 06:00 PM 1
Sat Naples, Italy 07:00 AM 07:00 PM 0
Sun Rome (Civitavecchia), Italy (Flight Departure) 06:00 AM --- 0

 

[MeatyPortion]

Looks like an awesome time. I hate you.