Sorry, Not yet.
Although it is an interesting idea, i'm not sure exactly how it would work, because duckduckgo does not have a bot that could be used for local indexing at this point.
A privacy-conscious local search engine would be extremely handy though, and a nice alternative to google desktop.
There are some interesting local search engines available, so i'll get back when I remember some names
EDIT: I believe I misunderstood the OP; I thought they were referring to a local file search 

Have you looked at local.com. They have a white label affiliate program and they seem open to partnerships.

Local should work in the US to some extent using the Yelp API. Where are you located? It is on my list to look into Qype for the UK.

LIKE set up but it doesn't seem geared for UK use, good luck