I want to know whether it is possible or not? to get Google's 3 layer types in openlayers, nothing more.

Just I came across a web-page about supplying private key from openlayers to google maps for business api. But checking on the Google Maps API page, it is asking for signatures which is hash of the query with a secret key for each request. I think it is for maps image requests also.which is contradicting with what the web-page says.

Is anybody working with Gmap for business api with openlayer. How it can be done? help is much appreciated.