The ESA SSA-NEO Coordination Center is the European Space Agency Center
for the Segment NEO of the Space Situational Awareness program.
It is located at ESRIN (Frascati, Italy).
Another good introduction to NEO's. This
site is written for the layman, so it has a highly accessible
description of the problem and what is being done about it. Includes
an excellent listing of future encounters with Potentially Hazardous
Asteroids, as well as the Risk
Page provided by the complementary JPL's impact monitoring system,
Sentry.
This is the center designated by the IAU as the
clearing house for astrometric observations. The MPC is responsible
for receiving, checking, and disseminating the observations.