Taksi, for interactive 3D applications

It's a good open source program that lets you record video games and other 3D applications. It can save these videos in any format supported by the system (which have the codec), such as DivX, XviD, etc.. It works easily, using the keyboard: just click the buttons (or use the default program) and you can now record, stop recording, make screenshots, etc.
Immediate and effective (if there are video screens, or for interactive 3D applications, because it works only with them).

Taksi