Atlanta Braves theme with a slider of the Braves' A as well as a lock screen.

Also, it seems Winterboard has some issues with the lock screen image change. The intended picture (the old style Braves logo) is there, but if it doesn't take effect, you can find it with ssh or ifile at /Library/Themes/Atlanta Braves Theme/LockBackground.png. Then just transfer the image to your photos and set it as the lock screen background.