Skype provides instant messaging, voice-to-voice and face-to-face video calling for free and is a great way to communicate right from your home or anywhere you have a wifi connection. Online consultations can take several forms including chat, voice and video sessions and using Skype provides a secure and convenient way for online communication. Group calling can also be very convienient with Skype as it's not always possible to get everyone in the same room at the same time.
Skype Links
Here's a little tutorial on downloading and setting up Skype: