You're pretty much right. Apple renders their entire UI to OpenGL textures, and uses their nice GPU and scene manipulation to get the incredibly smooth feel. An

You're pretty much right. Apple renders their entire UI to OpenGL textures, and uses their nice GPU and scene manipulation to get the incredibly smooth feel. Android, up until Honeycomb, renders the UI in software, which ties up the UI thread with redraw events as well as input detection. You'll see the limitations of Apple's model in mobile Safari: scrolling too fast gets you to unrendered sections of the page, which must be rendered and filled in software; as well as pinch zooming, where you get a blurry zoomed texture for a moment or two while the software re-renders the page and updates the texture.