There are many formal rules for how to refer to peers and understandably so, although I always get irritated with pedants who seem to insist that anyone who uses the most common name for a person is wrong - how many philosophers write about the "3rd Earl Russell" or whatever the formal term is? And my college at the University of Kent was always described as being named after "Ernest Rutherford" not "Lord Rutherford" - how do physicists, chemists and stamp collectors refer to him?
Nick Assinder reports that one of the newest ennobled peers is styling himself "Digby, Lord Jones of Birmingham" (BBC News: Commons Confidential: July 2007). I can understand why he may want "Digby" to still be there, but why not just style himself "Digby Jones"? Or even take a different title - what about "Baron Digby-Jones"? After all there was "Lord George-Brown".