Here's one for you! $19.99 at Toys R Us.
Ok, so it's a 12m+, but Ian's physical therapist has this toy and he fell in love with it there. He's figured out how to turn it on and he'll sit there for HOURS watching it light up, play music and spin. He's also figured out how to get the gears off and chew on them, although he hasn't quite gotten the hang of putting them back on. This is probably the best toy purchase we've made!