From ANSA:

Palazzo Pitti: Mythologica et Erotica (Mythology and Eroticism) at the Museo degli Argenti (Silver Museum) until May 15, 2006. The show features 213 works from Italian and foreign museums. The range of works on display is remarkably wide with paintings, murals, sculptures, ceramics, prints, jewellery, coins and various other precious items - all depicting erotic stories from ancient mythology. One of the best museum exhibits I have seen - briefly reviewed by us here.

Museo dell'Opera di Santa Maria del Fiore (official site): Arnolfo, The Origins of the Florentine Renaissance, 100 works charting the career of great architect Arnolfo di Cambio and his influence; until April 21. We saw this exhibit, which was great, as is the museo - highly recommended.