Striving4Zen

1 Mr. Beller's Neighborhood
www.mrbellersneighborhood.com
True, often funny stories about living and sometimes drinking Snapple in N.Y.C.

2 Hot or Not
communitywalk.com
One of the easiest interfaces to create your own mash-up (New York by microbrew, for example), even for newbies.

3 Real Estate Auctions
2realestateauctions.com
A great mash-up for people wanting to invest in hot properties.

Others of note:
OnNYTurf
onnyturf.com/subway
An interactive transit map lets you plan out your dream route.

Man Map
propertyshark.com/singlemen.html
The city broken down by rich men.

Housing Maps
housingmaps.com
An amazing map of Craigslist housing ads across the country. (Sadly, no one has yet tackled Missed Connections.)

CommunityWalk
communitywalk.com
One of the easiest interfaces to create your own mash-up (New York by microbrew, for example), even for newbies.

Gothamist Labs
gothamist.com/labs/maps
Useful events and information charted around the city, including concerts, meet-ups and pizza reviews.
http://www.nypost.com/entertainment/putting_down_routes_entertainment_.htm