MelZ:
Join "Cruise Critic" online and you'll make lots of friends on the ship real fast plus learn from more experienced travelers. Many members arrange private tours for small groups that are way cheaper than the cruise line's pricey shore excursions.
"Trip Advisor" is also a very helpful website. They rate hotels, tell about tours, problem areas (like pick-pockets), even how to get euros with no exchange fees at wholesale rate not retail rate. I use then all the time with much success.
Both sites are free.
http://www.cruisecritic.com/
http://www.tripadvisor.com/
I'll be in Barcelona again in May 2009. When you come back from Las Ramblas, you will ask yourself: "Where did all those people come from - and where were they going?"
What ship?
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