I've been to Venice, actually it is a great city for photos. But, for the casual American shooting along the canals it can be very dangerous. As for a lens, look for something wide. I used the Canon EF-S 10-22 along the narrow walkways along the canals. While shooting a church, I watched a woman with a Nikon backup to shoot the church front, and fell in the canal. There are no barricades to stop you from falling in. Of course you can walk to a bridge across the canal, but you may have to walk quite a ways. Wear good walking shoes in Venice, everything is on either stone, or concrete. I've never been to Milan, so can't help you there.