Recently, we have been working on each platform to get the platform-specific features to be encapsulated as plugins. Now, for the iPhone, that may take the shape of native controls, but for Android, we're working on a project for the plugins called PonyGap. Why did I call it PonyGap? Because chances are that you would use this app in a demo, and that you would most likely stick to the basic feature set of HTML5. Of course, you MIGHT use one of these, but generally not all of them.
Currently the first plugin feature that we added was the ttsHook. This will hook into the Android Text to Speech functionality and allow PhoneGap applications to be useful to people who may not necessarily have the best vision or coordination. We'll work on a better MobileSafari example and release it with the plugin.
This functionality was inspired by the Eyes Free work that Google did.
Update: This post is now obsolete, and there's a new and different method of creating plugins for Android. Please visit the PhoneGap-Plugins repo for more info.