Found this blog post from Google

Keeping up-to-date on the Gulf of Mexico oil spill
5/21/2010 03:58:00 PM
(Cross-posted on the Lat Long blog)

It is estimated that at least 6 million gallons of oil have leaked into the Gulf of Mexico since the Deepwater Horizon explosion a month ago. Cleanup efforts are underway, but the oil has spread extensively around the Gulf and along the southern U.S. coastline. Oil has begun washing up on the beaches of Louisiana and the delicate wetlands along the Mississippi River, and can spread to Florida and throughout the Gulf as weather conditions change. This sequence of images, coming from NASA’s MODIS satellites, illustrates the movement and growth of the oil slick over the past few weeks:

The first picture is a current look, and the others show how it got that way over the past month.