I have used Skype for years to have phone conversations over the internet. Skype allows video conversations, voice conversations, and chats. There is now a site where teachers post ads for other classrooms wanting to communicate through Skype. This is a relatively new way for classrooms to communicate. I wish I had had Skype available when one of my students had a grandparent living in Japan.
To try Skype visit http://www.skype.com/
To view Skype Want-Ads visit http://skypeinschools.pbworks.com/Want-Ads