I first became acquainted with jezzball in 1997 when it came with my first personal computer. The concept is simple. There are balls bouncing around, and you have to eliminate the space that they bounce around in. As soon as you get the space down to 75% of what it was, you move onto the next level. And the next level simply adds one more ball, making it more difficult. It sounds stupid, but its ridiculously addictive. My brother Scott was at one point as addicted to it as I was.
Now that I've found where to play it online, I fear for my productivity. If you click on the link below, be warned, it could affect your life.