To take the idea of using
inanimate objects as
RPG aids just a little further, try this.
First, go to Radio Shack or some place like that, and get a turbo controller for your Playstation. (Namely one with a switch which, when set, will interrpret the holding down of a button as the rapid-succession pressing of a button.) It's also important that you get one which had a d-pad that is composed of one shaped plastic piece (sort of like the pad on a Super Nintendo controller.) The more space between the casing and the pad, the better. These generally cost less than $10 USD.
Back at home, plug the turbo controller into slot 1 and fire up Final Fantasy IX. The key here is to give all your characters auto-regen, and then put them somewhere on the overworld. Now, for the nifty part.
Find a screwdriver, and then hold down and right (or up and right, up and left, down and left, whatever you want. Make sure you're walking into the clear, not into an obstruction.) Here's the trick, jam the screwdriver into the gap between the pad and the casing on the other side, so it serves as a wedge. If you did it right, the pad should stay depressed and your characters should run in a circle without your intervention. It's important, now, to make sure they do manage to complete the circle without hitting anything. As long as they stay in constant motion, you're golden.
Now, after a few seconds you'll hit a random encounter. At this point, switch on the turbo function and stick the controller under your chair as you did before. This will a.) negate the effect of the wedged d-pad, since the X button is firing in such rapid succession b.) do all your attacking for you and c.) get you through the "gained exp" screen and back to the overworld, all without your intervention
Once you hit the map again, you'll walk in circles until you encounter a battle, and the cycle will repeat. This works so well in FFIX because of the auto-regen ability. Monitor your little rig here and make sure your characters are not taking any real HP loss during battle. In fact, they must come out with more or equal HP or they will die, eventually. Once you have them in an area that's easy enough, turn off the TV (to save electricity!) and then go to work, go to school, go to sleep, whatever. When you come back, you should have some nice level 99 characters.
Enjoy!