This feature is already available in the IP Keyswitch. It works differently than the Call Pickup used in Call Manager though. The pickup is not used to answer someone else's phone. It is used to pickup a call that is on hold.
Example: Ext. 3000 answers a call. He/She places the call on hold. Person on ext. 3333 presses "Pickup" and then dials "3000". This will pickup the call holding on ext. 3000.
