Currently have a campaign running with Overture UK and noticed several hits from a new referrer showing up this last couple of days. The referring url implies a specialised search engine of some kind, although couldn't seem to access the site properly (resolves, but just getting a standard type message). Anyway, looked up the registrant and it comes back to Overture (only registered in June) with name servers also as Overture.
Maybe I'm not up to speed here, but I wasn't aware of Overture owning any search sites apart from their own brand?