CallLockScreen is compatible with iOS 6, it allows you to block the LockScreen during phone calls

  CallLockScreen is a tweak presented by me a few weeks ago when I told you that it blocks the LockScreen of your iDevices during phone calls. The idea is to eliminate the need to use the proximity sensor to answer calls, this component of the iPhone sometimes having functional problems. The tweak works as soon as it is installed and to use the terminal during a call you just have to unlock it.

  Since yesterday, CallLockScreen is also compatible with iOS 6, and in Cydia you can find it at the price of $1.99 in the BigBoss repo.