We use GotoWebinar for our large, public audience meetings. It costs us something close to $79 / month and works well for the purpose.
When we have smaller meetings with clients, vendors or other parties, we use Skype and are working toward Google+ Hangouts. The beauty behind these two platforms is that a lot of people already have accounts with Skype or Google, so they are not signing up for a new account for each meeting they participate in.
Skype is our preferred choice for one on one meetings, but Google+ Hangouts is becoming our choice, especially for meetings with multiple parties.
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