Video conferencing
In the area of video conferencing or [1], there are some big names like Webex or Citrix's "GoToMeeting" (wp:GoToMeeting) that garner most of the market share. Newer companies such as "Wired Red" offer products to provide video conferencing [1] too. It's great to see these products and services, however there is always a limitation on what platform the software runs on and/or the solutions are still costly. Enter the free software video conferencing systems. Right price, fuller technology support and more features than proprietary systems. The truly "free software" video conferencing market is a relatively unheard of category, but raising eyebrows for venture capitalists and [2] alike.
While pure wp:VoIP systems like Asterisk handle telephone requirements, DimDim is the company and product leading the video conferencing market. What makes these new applications compelling is that they not only allow voice communication, but they also do video and allow desktop or application sharing between groups (not just a two-party phone call). The age of telecommuting is here.
Some in the "free" as in cost category are still pretty good choices. The most ubiquitous in this category is Skype. Skype is not "free software" because it's not open. But it does do voice and video. We'll add more about Skype later.