NYC Street Parking web maps
On a much lighter note, anyone who's lived in, or spent appreciable time in, New York City, is familiar with the vagaries of alternate side of the street parking rules. However, it's damned near impossible to find out about these regulations online.
Seems to me there is a crying need for a simple map of Manhattan with clickable links indicating the appropriate parking rules for whatever neighborhood you've selected. There are 4 million or more cars in Manhattan on a typical day-- ain't that a big enough market for someone to go after?