I know that it is possible to overclock with emulators, etc, but is it possible to overclock anytime? It could maybe be usefull for movies, and maybe multi-tasking. Just an idea, and probably a bad one, but an idea none-the-less.
No, the overclocking is done through a library call usually, which is only done if the author adds it. Most games are designed for a certain Mhz and might act strange at others (slow or too fast)