An ex-voto is a votive offering to a saint or divinity. It is given in fulfilment of a vow (hence the Latin term, short for ex voto suscepto, "from the vow made") or in gratitude or devotion. Ex-votos are placed in a church or chapel where the worshipper seeks grace or wishes to give thanks. Shrines decorated with ex-votos are often the destinations of pilgrimages.

Ex-votos can take a wide variety of forms. In the church of Notre-Dame-de-la-Garde in Marseille, France, the site of a major local pilgrimage, the ex-votos include paintings, plaques, model boats, war medals and even football shirts given by players and supporters of Olympique de Marseille, the local team. In a corner of the basilica of Saint-Joseph du Mont-Royal in Montreal there is a tall wall with thousands of crutches and other supports from those Brother André supposedly healed. The Pope recognized the authenticity of the miracles and beatified Brother André in 1982.
http://en.wikipedia.org/wiki/Ex_voto