US President Barack Obama told three lucky schoolchildren to say cheese as they posed for photographs.
Margaret McDonagh, Colm Dunne and Onyedika Ukachukwu were left with the memento of a lifetime after being chosen to ring a Peace Bell during a tree-planting ceremony.
Mr Obama told them: "You did an outstanding job. Excellent."
Onyedika, aged eight, is the Irish-born daughter of Nigerian parents and attends Scoil Mhuire in Blakestown, west Dublin.
Nine-year-old Colm, who is visually impaired, attends Scoil Bhride in Paulstown, Co Kilkenny.
And Margaret is a member of the travelling community. The 10-year-old is a pupil at St Francis of Assisi Senior School in Priorswood, north Dublin.
Mr Obama, his wife Michelle, Mrs McAleese and her husband Martin, chatted with the youngsters before the group posed for photographs.
"Everyone say cheese - that's what we do in the United States. We say cheese," Mr Obama said. "It's wonderful to see you all."