They love it. They have had it for a few days now and still love to play with it. It's funny, they chase the ball by physically running around the toy in circles.
It's called Cheese Chase by Petstages: http://www.petstages.com/default2.asp
I bought it at Petsmart. It wasn't very expensive either, about $14.
Three fun activities for three times the fun!
Translucent ball track offers hours of chasing fun for your cat
Swiss Cheese center offers challenge and interest with another ball to chase
Plush mouse on spring is filled with catnip to attract kitty!
Gentle spring action adds more action to this fun filled toy station
Non skid bottom keeps toy in place