Here are some cool projects I've learned about at ESA:
EREN: Ecological Research as Education Network- creating a structure for ecologists at primarily undergraduate institutions (PUIs) to collaborate on larger-scale projects
EcoSynth- this might be the coolest thing I've seen at ESA. The web page doesn't do it justice right now! You can use a remote controlled airplane with a digital camera to construct a 3D image of an area.
DataONE- an online repository for data and metadata.
eBird- enormous citizen science project in which anyone in the world can participate! They have thousands of people contributing every day! Wanna join?
Not a link, but I witnessed something that deserves a shout out. I saw a grad student give a talk with no slides and no notes with a 20-minute can-you-do-this-if-your-advisor-doesn't-show-up warning. The penalty for a no-show talk or poster is nothing to scoff at, but if someone else gives your talk you're off the hook. This woman gave her advisor's talk with basically no warning, and did a hell of a good job.
**Added August 7, 2010**
Gigapan- seriously awesome and interactive photography. Thanks for reminding me, Eugenie!