There are a growing number of free tools that allow you to conduct online meetings or even provide online courses. Some stand alone while others can be used on conjunction with one another to create an environment that enables you to share desktops and converse with one or more individuals. For example, you can use Skype and a desktop sharing tool to conduct a virtual meeting.
Desktop Sharing
Online Course Platform
Chat Services
Tiny Chat - set up a free chat room and talk with friends, colleagues