EDIT: Rainfreak has been kind enough to take a crack at this and has made some progress!! He will be starting his own thread once he is ready to release it so he can recieve the propper thanks he deserves!
THANKS RAINFREAK!
OP: Here's an idea... when you turn your phone off, it locks... when you turn it on, you must roll your thumb/finger to the right around the wheel of the diamond to unlock it...
as you wheel around, the white line around the circle begins to fill from the top, moving rightward around...
sorry for the poor image quality, i just threw it together as a thought.
I hope a developer can throw this together, prolly isn't hard at all and would really be cool for the diamond. Better graphics and glowing line ofcourse.