VATICAN CITY (AP) — Florence's famed Duomo is cleaning up its act, removing centuries of graffiti from the cathedral dome interior and letting new visitors leave their mark digitally instead. The cathedral launched a pilot project last year in its Giotto-designed bell tower to allow visitors to use a touchscreen to leave a digital message rather than deface the 14th-century structure. To date some 18,000 digital messages have been left, and the project was such a success that the cathedral administration said Thursday it was extending the project to Brunelleschi's dome that dominates the Tuscan city. The sales pitch?Read more on NewsOK.com