Just watched this great video that PopCandy tipped me off to.
To promote Sony's new movie, The Water Horse: Legend of the Deep, they rigged up a holographic water display in the middle of Tokyo Bay. The rig projects the monster onto a haze of water.
LiveLeak noted: What you're seeing in the video wasn't added after the fact—that's actually what it looks like in real life.
The feat uses a water screen (carefully sprayed water jet) and exact light projections to create a giant pseudo-3-D Loch Ness "Water Horse" monster in the ba More..y.
Really a well done piece of advertising and technological demonstrative achievement.
The people over at Geekologie had an amusing write up.