DOWNTOWN
This is Lower Manhattan where there are no numbered Streets or Avenues.  I included pictures of Chinatown, Little Italy, Soho, the Financial District and the Seaport.  Chelsea, Tribeca and the Alphabet City are nice, but once you've been overwhelmed by Midtown, these neighbourhoods look lacklustre.
A view of the Brooklyn and Manhattan Bridges from the Seaport area.  I didn't get too close because I wanted a decent shot of both, but I think I failed :(
Mott St. in Chinatown.  This is one of the most vibrant Chinatowns I have ever seen, and I have seen plenty.  It's basically the only place south of 116th St. where you can find a bargain. 
Ground Zero.  This is the primary reason why I went in September 2003.  When I saw all the construction going on in the foundation, my heart sank. 
Little Italy during the San Gennaro Festival.  I guess this is what still keeps it alive.  I would suggest to go the Bronx or Brooklyn to see real Italian neighbouhoods.  There's good granita here though!
The New York Stock Exchange on Wall St.  Not the place to make money nowadays, but still, it has nice architecture.  Everyone you see on the street here is in a suit rushing past you faster than the cars.  Great atmosphere to check out.
The Seaport near Pier 17.  This picture is taken from a distance because I didn't want to faint from the stench.  But don't be fooled, this is a place to visit with shops and museums all over explaining its history.
A building in Soho.  The neighbourhood is upscale with neat shops in the day, but this place lights up at night, especially on Houston.  The neighbourhood to go out if you don't have a place in particular.