Carnival Dream Mediterranean Cruise, Oct 19, 2009 - Venice

St Mark's Square / Basilica - here will be doing a tour: Venice Past and Present Walk: http://www.tours-venice-italy.com/venice-past-and-present-walking-tour-winter.shtml

Something probably similar you can do on your own is Rick Steves' tour - I prefer to have a guide I can ask questions of:

http://www.ricksteves.com/news/travelnews/0602/italy_downloads.htm  { St Mark's Square Tour and St Mark's Basilica Tour }