I have used a citypass before although I am not sure if I purchased them from the website or not. I think they were a nice value. I remember it including public transportation for 10 days and free admissions to a number of museums (and I tend to be a museum freak on long business trips and vacations -- I know, I know watch out nightlife).

Of course I would check and see how many of the attractions I need to visit and find out the individual cost.