Another angle, featuring the dome
Sightseeing in Tuscany picture - Although I didn't have time to line up & go inside, I read that the interior is faced with black & white marble, & has a gilded gold ceiling, frescoed dome, impressive granite Corinthian columns, & an elaborately carved pulpit. The interior was largely redecorated after a fire in 1595, which destroyed most of the medieval art works. This web page has a great photo gallery with some photos of the interior: http://www.molon.de/galleries/Italy/Pisa/