I'm just curious how this happens exactly, I assume the way it works for everything else in the system is to bring up a pic in your theme when it is supposed to be pulling the system files but since the wallpaper is just a color value how does that get put into the mix w/ winterboard or bosspaper or anything else out there that is doing this?
I am curious about this too as I'm currently setting up my theme manually with SSH to avoid the Winterboard slowdown. So if anyone knows where to locate the Wallpaper.png or the file that makes the background, please say so.
WinterBoard itself does not slow anything down, I am currently on 3.0 firmware and no issues at all? Wallpaper.png you can create yourself in any fashion to suit your tastes, just use Photoshop/Gimp/or Paint.Net and create a image size (320x480) or download an image you like off Google images and open it up in one of the above programs and size it to (320x480). As long as everything is named properly, it is read by WinterBoard or the iPod/iPhone If that is not what your asking, I am sorry and move on