What are some alternatives?
When comparing BossPaper and Pimp Your Screen, you can also consider the following products
Winterboard - Give your iPhone or iPod Touch a graphical overhaul!
Lockinfo - You can find this app in Cydia - Tweaks.
Dreamboard - DreamBoard lets you take control over the homescreen of your jailbroken iPhone.
Masks - A page about iPhone Software.
IntelliScreenX - Need to know where your next meeting is? Do you have any new email?
vWallpaper - vWallpaper lets you set a video as your iPhone's wallpaper.