ASP.NET Route configuration demonstrating how to mix REST and RPC style actions on the same controller.

RouteConfig.cs

public static void RegisterRoutes(RouteCollection routes)
{
    routes.IgnoreRoute("{resource}.axd/{*pathInfo}");

    // GET /api/{resource}/{action}
    routes.MapHttpRoute(
        name: "Web API RPC",
        routeTemplate: "api/{controller}/{action}",
        defaults: new { },
        constraints: new { action = @"[A-Za-z]+", httpMethod = new HttpMethodConstraint("GET") }
        );

    // GET|PUT|DELETE /api/{resource}/id
    routes.MapHttpRoute(
        name: "Web API Resource",
        routeTemplate: "api/{controller}/{id}",
        defaults: new { },
        constraints: new { id = @"\d+" }
        );

    // GET /api/{resource}
    routes.MapHttpRoute(
        name: "Web API Get All",
        routeTemplate: "api/{controller}",
        defaults: new { action = "Get" },
        constraints: new { httpMethod = new HttpMethodConstraint("GET") }
        );

    // POST /api/{resource}
    routes.MapHttpRoute(
        name: "Web API Post",
        routeTemplate: "api/{controller}",
        defaults: new { action = "Post" },
        constraints: new { httpMethod = new HttpMethodConstraint("POST") }
        );
}