I’m experimenting with AIR, because I heard saving a ByteArray ( for example encoded PNG or JPG ) should be quite simple. You don’t need PHP or another serverside script for this, just write directly on you disk. Well, just check it out.
I created an example of how to get it work. The image will be save in the same directory as your AIR application.
Click the read-more button to find out how to create a cool AS3 wallpaper.