LOL... sorry no constructive answer on the picture front, just goe this image of you pulling your phone out at work and having to explain why your wallpaper is your Mum!

As an alternative how about getting the Backgrounds app and choosing from their 20,000 odd images. I've got some beautiful ones.
I have just tried with a picture taken on my phone and dragged the orange box open to its largest extent and the image covers all three of my home screens fine on SE's stock launcher and is fine over the 5 screens I have on ADW. You can't have the whole picture if that makes sense, you have to select the area but once selected it seems fine.