A homebrew enabled PlayStation 3 console. As of now that mostly means having a custom firmware installed. Obtaining and installing such a software is out of the scope of this document. Sorry, but you’re on your own for that one.
At least one ScummVM supported game. The list of compatible games can be seen here: http://www.scummvm.org/compatibility/
The page http://wiki.scummvm.org/index.php/Where_to_get_the_games references some places where those games can be bought. Demonstration versions for most of the supported games are downloadable on http://scummvm.org/demos/