blown head gasket?

What are some signs of a blown head gasket. My car is getting poorer gas mileage, leaking oil from an as of yet unknown location, and recently has completly stalled. See "died while driving."

Thanks for any help,

Jai

The signs are as follow:
1.Coolant in oil bath after a short time the oil will have a milky color
2.Oil in coolant
3.If you unscrew the radiator cap with the engine running you will see bublles caused by the engine compression escaping in the radiator.
4.Alot of white smoke at the tail pipe.
You can have all of those simptoms or some of them depends of what failed, water mixed with oil means a failed head gasket, oil in coolant or bublles in radiator a hair fracture in the head or piston chamber.