not so good for hanging out, but the Museum of Islamic Art (big stack-of-cube landmark, at the end of the Corniche) is really amazing. The building is quite beautiful (particularly if you like _really_ shiny things), and the collection is very good. Iranian pottery, wonderful stuff... a full suite of armor for a Turkish knight and his horse... very refined calligraphy. Beautiful. The museum shop sucks, but I hope it will improve.