National Phenology Network
http://www.usanpn.org/ 

Project Budburst
http://www.budburst.org/ 

Phenology - Wikipedia 
http://en.wikipedia.org/wiki/Phenology  

Measuring Vegetation (NDVI & EVI)
http://earthobservatory.nasa.gov/Features/ MeasuringVegetation/ 

University of Montana Numerical Terradynamic Simulation Group
http://www.ntsg.umt.edu/ 

Boston University Climate and Vegetation Research Group
http://cybele.bu.edu/greeningearth/ge.html 

The Vegetation Index and Phenology (VIP) Lab
http://vip.arizona.edu/ 

MODIS for the North American Carbon Program (NACP)
http://accweb.nascom.nasa.gov/project/ 

MODIS Land Products Subsets
http://daac.ornl.gov/MODIS/modis.html 

Ameriflux Network
http://ameriflux.ornl.gov/ 

Global Geo-Referenced Field Photo Library
http://www.eomf.ou.edu/photos/