I put Jelly Bean on my Verizon Samsung Galaxy SIII using http://www.cyanogenmod.com/blog/cyanogenmod-10-m2.
I know that it should be possible for me to use my camera to take pictures quickly (without unlocking my phone). (See Is it possible to use the camera without unlocking first?)
But I haven't figured out how.
I use a 4x4 pattern lock screen.