Caller claimed to be with Hilton Hotels and knew my name, although I don't believe I've ever stayed at a Hilton. I said I didn't they'd be calling from a cell phone. When I called the number back a minute later, a recording said it was no longer in service.
Same thing here; it's been going on several times a day for the past 3-4 days (as of 4/21/08). I never pick up on numbers I don't recognize, so no clue who this is...