The problem I had doing something similar was getting the link to them. You need some other out-of-band communication method, whereas with skype you just agree

The problem I had doing something similar was getting the link to them. You need some other out-of-band communication method, whereas with skype you just agree to a time of the week when to sign on and call each other. Email sort-of works, but not as easily as the central logged-in lobby system.