If you were particularly skilled, determined and weird, you could build a robot arm and a computer vision system to save and restore games of pool on a real table. If you get to a point in a game that you want to save for later, you can just hit the "save" button, then a computer will take a picture and remember the position of all the balls on the table. Then, while you go away, someone else can play. Later you can come back, find that saved state again, and have the robot arm accurately replace the balls exactly where they were.
A system like that would enable other interesting options, too. For instance, you could save a trick shot setup to use over and over, or use it as an accurate "do-over" system when playing with less-skilled opponents. You could save a game and take it with you to play elsewhere, so, for instance, if you have to leave a party before you're done, the game doesn't have to stop there and then. You could even, if you were so inclined, play against someone over the internet, though it wouldn't look very exciting unless a robot cue attempts to reproduce their shot before the ball-placing arm corrects the table again. Also, the slight differences in your tables might make such a game a bit unbalanced.
Mokalus of Borg
PS - Some people have already built pool-playing robots.
PPS - Probably with mixed results.