Touch screen implementations and browser size

I have noticed something not mentioned much elsewhere when testing the PubCrawler on various devices. It is how much screen space is devoted to a web page. This is not a simply dependent on screen size as these screenshots show:

iPod Touch/iPhone 3.0 HTC Dream/T-mobile G1 Android 1.5 HTC Hero
iPhone Dream Hero

All the devices have the same resolution at 320×480 but the iPhone has the larger screen at 3.5 inches. The other two have 3.2 inch screens. It is obvious that the iPhone is showing less of the page, chopping off the bottom of the map. This is an important thing to remember for a single page web app like PubCrawler. The map should resize dynamically for each device which is something I might look into. Luckily the iPhone does not need the controls at the bottom thanks to multitouch pinch and zoom. The reason for the lack of browser room is the absence of physical buttons on the iPhone. This means it has to show more buttons on the screen which take up valuable space. Some people have wandered why there are so many physical buttons on Android devices but they are there for a reason: freeing up screen space and providing more options.
As mentioned before the Hero turns the entire screen over to the browser window forsaking even the notification bar. This leaves a big gap between the map and the controls at the bottom. Space for an ad perhaps? Maybe but you wouldn’t see that ad on the other devices!