Art can be found everywhere on the streets of Istanbul. I'm not just talking about graffiti, although there is a lot of that, but the art of architecture, movement, and humanity. Everyday scenes of the city, framed by a minaret or the Bosphorus, changed by the play of shadows, or lightened with a bit of urban humor. Istanbul can be both strikingly beautiful and thought-provoking, simultaneously... just like any great piece of art.
The city is far easier to walk than I'd feared, and public transportation is cheap, quick and efficient (if crowded). Most importantly, most of the major sights are packed closely together in or near the historic center. On one of our first days, we walked along the tram line from Sultanhamet Square (next to the Blue Mosque and the Hagia Sophia) to Beyazit: a short, straight walk during which we saw one historic treasure after the other.