Machinima is the portmanteau of the words - Machine and Cinema. It is the screencapture and production of video from 3d games and virtual worlds.
As educators who game or gamers who are also educators, we continually use Machinima as tutorials to change tacit knowledge into explicit knowledge. We also use Machinima to demonstrate the learning we see happening in games and virtual worlds. Oh and I did mention, we also like to create.
For example, here's a recent Machinima made for the 2012 ISTE SIG - Virtual Environments Machinima Fest.