Algodoo

This is something I found when I tried to create a 3-D hole. Im not really sure if this works on every computer but if you scroll in and out of the hole your screen should start flickering and you should get the same affect as the "hypnotising" disks. But even so its just cool to scroll through the infinitive *cough* hole.
WARNING!! do not click play if on a slow computer, there is a big chance of freezing (it did this to me . Otherwise it's cool. Also by zooming in in different angles you can make it look like you are going up/down/left/right.
Have PHUN