We now depend on the RestTemplate interceptor capability in Spring 3.1, which will be available in its first official release with the 3.1.0.M1 release tomorrow. Take a look at how we're using it e.g. in TwitterTemplate--it simplifies signing requests for protected resources quite a bit. 1.0.0.M2 will have a hard 3.1.0.M1 dependency because of of this; if there is a lot of demand for 3.0.x compatibility, we can discuss options there but initially I'm hesitant to introduce our own way of doing this when RestTemplate is what we're building on (and we want to provide a clear and consistent implementation path for ServiceProvider contributions)
Keith
Keith Donald
Core Spring Development Team