Here's something quick from The Australian Centre for Visual Technologies that I've been keeping my eye on for over a year now; Video Trace, a system for interactively generating realistic 3D models of objects from video. Unfortunately, there hasn't been an update on the project since then but it's still a pretty cool idea.
The user interacts with VideoTrace by tracing the shape of the object to be modelled over one or more frames of the video. By interpreting the sketch drawn by the user in light of 3D information obtained from computer vision techniques, a small number of simple 2D interactions can be used to generate a realistic 3D model.
There are a number of applications of the VideoTrace technology, including modelling parts of the real world for insertion into virtual worlds. You may want to model your house, in order to put it into Google Earth, or your couch, in order to take it with you into Second Life, for example.
There's a really cool video outlining the hows of Video Trace that's definitely cool.