New York is America's largest city, boasting 8 million people, and claiming to be a serious cultural center. This much is the good news.
The bad news is that in the 200 years since the filling out of the city, much of it is old, ugly, and falling apart. Construction grows more difficult by the day due to the virtue that half the infrastructure consists of things that no one is quite sure what it is, but is afraid of inconveniencing millions of people if they break it. Thousands of miles of obsolete gas, pneumatic, and other pipelines crisscross the city. New York is watered by two enormous pipelines. The pipelines have been in use continuously for over a hundred years, and the engineers are afraid that if they shut one down for inspection, that they might not be able to start it up again. Bad. A third pipeline is underway, estimated to be complete in 2010.
I think that all of the city landowners should pool their money with the city's for a massive rebuild. We would take a census of every person, every business, every structure in the city and what humans live and work there. Then we would move all 8 million people out into temporary structures (either in upper New York or in Montana) and level the city to the ground. We would then rebuild the city with all structures twice as tall and with better infrastructure. (Many buildings were built before such things as air conditioning and internet access, and retrofitting is proving a problem. These new buildings would be built with those in mind.)
Having rebuilt every last structure, and new pipelines and subway, we would then get out our census notes and move people back into the addresses that they once occupied. The census would enable people to continue to rent at the same address at the same rate as before. However, the twice as large building could accommodate new tenants as well, thus earning the landlord additional money. (This should be pleasing to all parties involved.)
We would, of course, insist on all the replaced buildings be up to code, with all the latest safety standards in wiring, fire prevention, and waterproofing. (New York is technically in a hurricane zone.)
I think that the increased quality, comfort, and lack of decay would revitalize the city. In addition, improvements to the subway system would make it faster and easier to get to work, as well as reach neighboring regions (such as pennsylvania and new jersey) for additional economic opportunities.
This would of course cost a ludicrous sum of money. Still, between all the building owners and the city, I think it could be achieved.