xkeyller is a very simple utility for X11 that kills whatever the foreground window is when pressing Ctrl+Alt+K using xkill and restores the default video mode using xrandr. It can be useful for games that like to take over your desktop and then hang themselves.
Download source (2KB). It contains a single C file and a Makefile. If you need to change the shortcut (or disable the call to xrandr), simply modify the code.