"Apophis was discovered in 2004 about 17 million miles from Earth on a course that would overlap our planet's orbit in 2029 and return seven years later. Observers said that the asteroid — a massive boulder left over from the birth of the solar system — is about 1,000 feet wide and weighs at least 50 million tons.

After further observations, astronomers reported that the asteroid would skim by Earth harmlessly in 2029, but it has a one in 44,000 probability of slamming into our planet on Easter Sunday, April 13, 2036.
...
First, the Shapiro committee is supposed to propose the best way to detect and analyze 90 percent of the so-called "near Earth objects'' orbiting between Mars and Venus that are wider than 460 feet by 2020.

About 20 percent of these are identified as potentially hazardous objects because they might pass within 5 million miles of Earth (20 times the distance to the Moon).

More than 5,000 near Earth objects, including 789 potentially hazardous objects, have been identified so far. Johnson predicted that future surveys will find at least 66,000 near Earth objects and 18,000 potentially hazardous objects."
http://www.mcclatchydc.com/251/story/58025.html

Linked from http://pajamasmedia.com/instapundit/

And
"So far, NASA has spent $41 million on asteroid detection and deflection, but the Near Earth Object Program is running out of money."