Tend to disagree with fellow KLouis on Otranto; it may not be on par with many other Puglia's beauties, but definitely worth a few lines home about.
Goes without saying that a stop in Lecce, specially at night, should be on your agenda too.
Regarding beaches near Otranto you don't want to miss Torre dell'Orso e Baia dei Turchi. Just few kms apart.