Don't don't don't don't don't do this, omg don't.
I spoofed 6.0 on my 5.1.1 device, and it broke my app store and iTunes store, forever. It like registered my device at apple as having ios 6, so when I open either store it begins to load the redesigned iOS 6 store, but obviously my device doesn't have any of the required graphics or code, so it just sits there, blank. Even changing it back to 5.1.1, rebooting my device, and going into safe mode doesn't fix it.
Just glad 6.1 Jb is on the horizon.