GamesRadar: "We've done tests, and we've found that there's a .001% chance you're going to read any of this. Odds are you're going to immediately start clicking the "Next" button, scrolling through the dozens of images we've hunted down, resized, and saved for use on the PlayStation Vita. But if you are reading this, it's likely because you haven't figured out how to add wallpapers, in which case you can just look below to find out how to get all set up.
How to add a wallpaper to your PlayStation Vita's home screen
There are two ways to get the wallpaper onto your system. The first is to just open the page on the Vita's browser, hold down on the image, and save it. There, you're done! If you want to use your computer, though, there are a few steps you need to take."