Cool MODIS NDVI tool pointed out to us from Jenny P.

This toolbox contains scripts that download NASA satellite imagery from MODIS and import it into ArcMap. The four data products currently supported are: evapotranspiration, land surface temperature, normalized difference vegetation index (NDVI), and enhanced vegetation index (EVI).

These products are available for the entire surface of the Earth at 1 km resolution and for any month going back to January 2000, when MODIS first launched aboard the satellite Terra.