Dynamics CRM 2011, Call multiple entities in one go

I am working on application which all the master data from CRM entities seperately using Microsoft.Xrm.Sdk (CRM web service).

Issue is, currently we are calling all entities seperately from .NET, which makes WCF call earch time.

I am trying to implement solution, in which I will call seperate entities in one go, so that in 1 WCF call I have all the master data.

So Sql Equivalent will be Select x from Entity1; Select y from Entity2

I am using QueryExpression & then calling RetrieveMultiple(query) method.

Any help will be appreatiated.

Thanks, Div