[yardie]

As an iPhone, Android, and WebOS user hands down WebOS has the best navigation implementation of all of them. Activities are in cards. Cards are stacked in the order you use them. You can go from phone to contacts to webpage in the same stack and you can pick any item in that stack, no backbutton needed. It has a dedicated gestures area which is more powerful than 4 buttons and definitely better than one.

[cpeterso]

I imagine Android could easily display Activity switching and Activity Stacks as webOS-like cards. RIM engineers quietly admit they stole the PlayBook's app switching GUI from webOS cards.

[yardie]

Google did hire away the designer, Matias Duarte, from HP/Palm. I wouldn't be surprised to see more WebOS-like GUI actions in future versions of Android.