Handipoints - Make Fun of Work!. It is free to join and lets you put together chore charts and behavior charts. It is interactive so it makes it fun for the kids. If you kids like virtual pets, like Webkinz, then they might enjoy this too. They earn points for their chores. The points can be redeemed to buy stuff for their virtual cat, or they can save points to get to a predetermined goal for an actual reward, trip, etc. We found it very easy to use and I was amazed at how much personalization you can put into it. It even lets you keep more than one chart.

http://www.handipoints.com/