How A Product Placement Strategy Works from AdAge looks in depth on how Yahoo is promoting its Yahoo Local service through The Apprentice television show.
Apparently, one episode last season got a ton of people to try searching at Yahoo for "apprentice ice cream," though it's unclear if the did this on Yahoo or Yahoo Local.
Yahoo Local is mentioned even more as part of the current series. How much for the placement? Yahoo's not saying. See also The OC Arrested By Ask Jeeves, Too for more on product placements in television for other search engines, albeit unpaid ones.