I know most of us have been through this situation when we dont want to attend some calls from a specific people or may be from a specific group.Well recently an app has arrived on Cydia AutoAnswer that would allow to which will auto answer your phone calls and also facetime calls.
This app would work on jailbroken iPhone 4 , iPhone 3GS and iPhone3G.If you ask what different in this app from others , the answer would be this app has the ability to auto-answer some specific number which you dont want to answer.Apart from this it also has the feature to attend Unattended Videoconference and Remote Area audio and video surveillance too.
So , with this app you just have to pick the number that you want to avoid and then this app would then take care of that call forever.You can get this app from Cydia for $4.99 and I think this app is good enough for this price.