Isn't it soooo cute?! Both of my cats play fetch. When Amadeus was a kitten and I lived in a 2 story house, he used to chase this little ball down the stairs, bring it back up, and I'd sit at the top of the stairs and throw it down again. I would also sit at the end of the hall and he'd fetch paper balls.
Now sometimes I'll wake up and the other cat, Sebastian, has brought his "nippy mouse" on the bed, so I'll throw it down the hall, and he'll toss it around then bring it back.
Once I was at the computer trying to get some stuff done, and Amadeus had his fishing toy (long stick with the string and some attachment on the end) at my feet ready to play, meowing and meowing, but I wasn't ready to play yet. Out of annoyance I threw the toy across the room, and he went and got it and brought it back! Obviously he didn't care how I played, he just wanted to!