I've tried numerous REST clients and by far the best I've used is the Chrome app: DHC.
DHC (aka Dev HTTP Client) is designed and developed by a developer for developers to make direct HTTP resource discovery, manipulation and testing more easily. Beside the main function, sending/receiving custom HTTP requests/responses, it allows permanently to save a request to a local repository for later reuse and moreover the request declaration can include variables that are context specific. With the use of contexts you can easily switch between various environments without modifying request declaration. (e.g. from a test environment to production)
