If you want to try a different itinerary have a helicopter ride over Venice, it's a great experience...a little expensive but worth a fly..
From the airport of the Lido there are different options at diferent prices: 6 minutes at 55 euro, 10 minutes at 99 euro, 17 minutes 169 euro and 25 minutes at 249 euro...families get a 30 per cent discount.
See their site at www.heliairvenice.com