Responsive Design + Server Side Components (RESS) is an idea that makes a lot of sense. The concept is that you use a server-side mobile detection method such as WURFL (http://wurfl.sourceforge.net/). Then you send up a different version of page components, different sized images, and so on. We could then change the wrappers around the page content and the navigation to use jQuery Mobile just as easily as any home-brewed markup. The beauty of this approach is that everybody gets the content that is right for them without the bloat of typical responsive design and it's always on the same URL.
The first time I saw this idea proposed in writing was in an article at http://www.lukew.com/ff/entry.asp?1392 by Luke Wroblewski (https://twitter.com/lukew) in September 2011. In it, he outlines the very performance problem we now face with images. Luke meant this as a way of doing pure responsive web design without any kind of mobile framework.
WURFL can tell you...