How to implicitly cache response messages in a WCF request-response pattern?

How can I implicitly cache response messages in a consumer application that calls one or more underlying services using WCF and the Request-Response messaging pattern without changing the code of the application in question? My caching option is memory.

Scenario:

• Windows Form Application as a Consumer
• 30 plus services hosted in IIS
• Both clients and services are under my control

I am currently considering the following items to implement:

• BeforeSendRequest / BeforeSendReply
• Or a custom binding that I could perhaps comment on in each service

I would love to hear some options if you mean. Thank!