Friedrich Kirschner came up with a 3D scanner that's made out of LEGOs, a bowl, a webcam and milk. What's up with the milk? Well, he dips in whatever he wants to scan in the milk, then takes shot after shot as he pours in more milk. By measuring up the milk in each shot, he can get a semi-accurate outline of whatever he's scanning.
The only problem is whatever you're scanning becomes covered in milk. It's actually pretty difficult to get out, as my mum found out the hard way every morning since I liked to chug a gallon of it before I went to school.