Brad Pitt spent yesterday afternoon taking a stroll in Venice by himself, though he got a hand from bodyguards when he hopped into a water taxi. It was a rare moment alone for Brad after a family-filled week with his parents, Bill and Jane, in town. The older Pitts helped Brad keep an eye on the kids while Angelina filmed The Tourist, even accompanying him and the children for outdoor park fun when they weren't hanging out on the balcony. The Jolie-Pitt family is currently abroad to support Angelina's work, but today is a special one for Brad's passions — the environmentally friendly actor is among the stars who stay eco-conscious on Earth Day.