In Mexico, a form of votive offering that goes well into the arts is that of the Ex-votos.
I am not sure if you folks are familiar with Ex-votos, but in case you're not:
An Ex-voto is an artistic expression of thanksgiving for an answered prayer Usually Ex-votos are graphic, but they can also be poetic, or both.
I see a great parallel between the Byzantine theology of an Icon, and our Ex-votos in the sense that Ex-votos need to represent the favor asked and received in pretty much the same way an Icon has to represent the theology of the scene it depicts.
Ex-votos are almost always tied specific shrines or images, and therefore, the right place for an Ex-voto to be is right there in front of the image or somewhere inside the shrine. But after some time the Ex-voto is removed by the keepers of the church and then only God knows what happens to them. Some are preserved as pieces of fine art, some others are offered for sale, and yet some others are simply discarded.
You can see (and even purchase) some of them here: http://www.votiveart.com/catalog_artwork/exvoto_splash.htm