blah... I can't find it either. I swear there was a way.
Edit: I think the launcher would have to be changed.
I know ADW Launcher doesn't have an option.
I think LauncherPro has this. Actually, I'm pretty sure it has this option.
Press and hold on an unused part of the desktop. Choose wallpapers, then multi-photo. Only add one photo and it will not scroll.I think its because of the update...before it, i had disabled it, but now....