I bought this a few weeks ago.    http://www.smartcatbox.com/  Since Scooby's drinking and peeing so much, and Fizzy is drinking a little more, the clay litter we use gets saturated pretty quickly.  So I started looking around and found this on the Felinediabetes.com site.  It looked promising so I thought it would be worth a try. 

We used it for 4 days, and then went back to the old one.  The resevoir gets filled rather quickly with 2 cats using it, and I was afraid of an overflow if it got neglected for several hours.  Both cats would use it to pee, but would go upstairs to the 2nd clay box to poop.  At the end of 4 days, I saw Scooby walk up to it, stare at it, and then ran upstairs and peed in the clay. 

It's a good concept, and maybe if you have just one cat, overflowing would be less of a concern.  Also, after the short amount of time, I started to notice a slight odor in the pellets.  The box came with directions for cleaning, but I never got that far.      $100 ($76.00+ $25.00 s/h)  down the drain.  Anyone want it?