I have two ArcGIS Servers running on two different machines: one is ArcServer 9.3.1 and the other is ArcServer 10. The services in 9.3.1 machine is accessible to both ArcGIS javascript API and Google map API for creating web applications. But the service in 10 (which is identical as to 9.3.1) can only accessible in ArcGIS API, not in Google Map API.
The following two examples uses the services from ArcServer 10 in ArcGIS API and Google map API.