Here are additions to The Best Ways To Find Other Classes For Joint Online Projects list:

Project Peace

Schools Around The World

People to People International’s School and Classroom Program

Online Projects 4 Teachers

EFL Classroom 2.0 — Classroom Connecting

Class 2 Class

Here’s a good blog post, including additional resources, on connecting to other classrooms. It’s by Julie Lindsey.

The U.S. Department of Education also has an extensive list of collaborative projects.

Global Collaborations