How often do you change your phone's wallpaper? (poll results)
You can often tell a phone line's generation simply by the stock wallpaper used
Others would change their stock background with something else that is provided by the manufacturer out of the box every now and then, while some would go to greater lengths and install a wallpaper app that gives them access to millions of tailored images to pick and choose from. There are even apps that will change the wallpaper for you every day if you wish, so that you never get bored looking at one and the same screen. You have to be careful with automatic swaps, though - you don't want to end up with a bright set of icons on a bright background, or vice versa.
Things that are NOT allowed: