gmail chat for master

Hi all !
it might be interesting for the different groups within the class to use gmail.com (from google) as a means of communicating. I have been using the "chat" function within gmail to contact friends both in paris and abroad and it really works well. Do hotmail and free have similar functions ? If anybody needs an invitation to gmail just let me know by mail, I have some invites left… we can talk about this Monday afternoon.