Madeline vanished during a family holiday in Portugal in 2007 and despite a massive search has never been found. Students at Davis College in Mallow, Co Cork, were so moved by the plight of the McCanns and other families who had loved ones disappear that they decided to do something practical to help.
The 23 students, supervised by teacher Kathy Kilgallon, created a special Forget Me Not website and a related poster information campaign.
The poster campaign has been supported airports including Cork, Shannon, Knock and Farranroe while both Irish Ferries and Stena Line have also come on board.
The posters aims to cover all Irish ports and airports so anyone leaving the country is reminded to let someone know their movements.