Yes, I looked and Level 3 was noted as the service making call completion for Goog-411 last May.

In a blog entry last fall a commenter noted that VOIP, Inc was doing call completion for the click to call feature that was being tested in Maps.

Obviously, google has tried a bunch of these folks…hey maybe we can start a buyout rumour?

I presumed that both this and the previous mention of (I think) Level 3 Communications were a toe in the water of ad sponsorship.

Or, alternatively (and in a similar vein), they were allowing a “sponsor” to pick up the actual cost of call-completion as a precursor to a truly ad-driven model.