If you're looking for time-wasting eye candy based on disrupting gigantic cellular automata simulations of theoretical computer science concepts (and who isn't?), this is just what you're after:

1. Download Johan Bontes' awesome Life32, an implementation of Conway's Game of Life for Windows.
2. Download Paul Rendell's astounding pattern: Turing Machine implemented in Conway's Game of Life.
3. Run it for a while, and marvel at the complexity of the parts interacting.
4. Stop the pattern running, and go into draw mode (Options - Draw mode). Make a little squiggle somewhere off at the edge of the pattern.
5. Run the pattern again. Chances are good your squiggle will generate a glider headed into some part of the Turing Machine. It will gradually cause complete chaos.
6. Repeat as desired. Try different types of squiggles, in different places. For extra fun, imagine the rogue glider is Luke Skywalker, and the Turing Machine is the Death Star!