See http://www.research.att.com/~smb/papers/piara/index.html for a
paper on the subject. (We held a BoF at the IETF many years ago; there
was sufficient pushback that we didn't pursue the question.)
--Steve Bellovin, http://www.research.att.com/~smb (me)
http://www.wilyhacker.com (2nd edition of "Firewalls" book)
I just *knew* such an obvious idea couldn't have been mine alone. 
When did you present your paper? The last reference I see is 1996.
What sort of pushback did you receive? Perhaps the experience of the past few years might suggest revisiting the question?
We held a BoF at the IETF many years ago
fyi - the mandate for the BOF was that the discussion had to
talk about a Market-based address allocation and concerving routing
table space at the same time
it was quite a good BOF
Scott