The surface of a computer and of computer-alike devices like smart phones or gps navigation are well styled and designed. Characteristic examples of those stylish devices are Windows Vista or any Apple device. There are menus and windows popping up, whirling arround, scaling and zooming, fading in or out.

From a programmers perspective these effects of course are unnecessary and categorize as toys. They require lots of code and processing which might be better spent somewhere else. For example in security related topics like hardening the applications running on such devices against hacking and theft of personal information.

Jonathan Zdziarski affirmed the programmers intuitive perspective when finding out the iPhone takes screenshots for zooming the screen in certain situations. Those screenshot leave a footprint in the iPhones memory potentially allowing others to view information ever displayed. You better think twice before selling your iPhone.