Just search for 'iPhone' at Yahoo and see the sponsored results.
http://www.digg.com/apple/Apple_and_Cisco_Linksys_started_a_Pay_Per_Click_war_for_the_iPhone_brand
http://www.digg.com/apple/Apple_and_Cisco_Linksys_started_a_Pay_Per_Click_war_for_the_iPhone_brand