I'm so excited about this potential for learning. Currently my son and I are involved in the Trans-Amazon Expedition.

http://www.wildernessclassroom.com/amazon/index.html

This is another great advancement in armchair travel indeed!

A group of explorers daily upload podcasts, videos, pictures, and other communications that the students read and respond to. Sometimes there are decisions that are made by poll vote, where the students get to direct the team. It is a true cross curricular learning experience. Google Earth helps students keep track of where their online teachers are and adds an extra dimension to the study of geography.

Children are able to interact with the experts through chats, and email. The team is available through email to the registered students.

It has been a very positive experience. I am seeing more and more projects like this.

More collaborative projects are located here:
http://www.k12science.org/collabprojs.html