Is it possible to use EF 4.0 without having a dependence on .NET 4.0

Lets say I build an Service Layer wich deals with POCOs coming out of an repository. The Repository is aware of the EF 4.0 and deals with POCO generation and so on. But that does also mean that my Rep开发者_Go百科ository will have a .NET 4.0 dependency and so my Service Layer which consumes the Repository will also have a .NET 4.0 dependency...even if its dealing only with POCOs and has no clue about the Entity Framework at all. Is there any way to work around this?

You could expose your EF entities using a WCF service - your server-side would be .NET 4 specific, obviously - with EF 4, .NET 4, WCF 4 - but the consumer / client doesn't have to be - if can be anything from any other .NET platform to PHP to Ruby to whatever might be calling your service.