google vs overture #'s difference any1 know??

[babymaker]

anyone know what is the google to overture ratio when figuring out hits per month relative to keyphrase?? i.e. if you use the overture keyword tool and overture gets 1,000 a month for "whatever" what does google get 10,000 - 100,000 a million?? is there a general calculation available?? i am sure it flexuates somewhat depending on keyphrase but am pretty sure it is basically the same. very curious if u know the answer. also, is there any google keyword tools around yet?? i have never heard or found one.

thanx