This info is based on my Huawei U8100 Android phone - I would imagine others are same/similar. You can use my method as a guideline. As one previous post said, default size for wallpaper is 640x480, which is true. The phone takes it and stretches it across all panels from the main screen. However if the image has an object in it, you will be 'zoomed' in to the point that it's pointless. Lets say, a friend's face or a logo. Even if you navigate left and right to other pages, it's annoying. Here's my fix. Create a file 1.5x the size of the original image (i.e. 960X720), and paste the original picture right in the center (I suggest black borders). Then, when you upload it to your phone, and use maximum size on your wallpaper selection screen, your point of focus will be nicely placed in the center main screen. On my phone, I only navigate left/right, so the black borders on the top and bottom aren't even visible. In the case of repeating patterns, this wouldn't matter. It won't always be perfect, but certainly good. Now I've got a well placed Star Trek logo on my screen.