Mine has yet to get an iPhone although she's downloaded some apps and games for it so she'll have a stash when she gets one. Yet, of all the apps and games she's downloaded, I can only see her using a handful of them. She plays a lot of time management games on DS and doesn't play any of my games although she'll play fighting games with me from time to time, like Virtua Fighter or SoulCalibur. It's funny because all she does is press buttons but sometimes ends up getting through my blocks lol
My GF was never into games before, but loves the iPhone. Totally loves Pocket God like crack, and has quite an addiction to Edge. There are probably others, but those are the main two. ..She has her own DS, and as soon as there's a good Zookeeper game on the iPhone she will no doubt be taking total control of the phone.