Android applications face a number of challenges that other mobile platforms may not have to deal with (yet). Android is available on a wide variety of hardware, each having a different screen size and pixel density (DPI), sometimes with a physical keyboard and sometimes without a touch screen (e.g. Google TV).
BuildMobile: Android Layouts: Resolution and Orientation Solutions
Bruce Cooper is an IT consultant who feels that in order to be able to serve his customers well he should have an understanding of the different technologies that are out there, and how they work. The best way to learn is through doing, so he often takes on small side projects to pick up a new technology.