MindRocket Media Group we've been using FreeConferenceCall.com for our meetings and it has worked out well.
FreeConferenceCall.com makes it easy for anyone to quickly create a free and private conference call number. To create your account simply visit the site, enter your email address and choose a password. The service will then generate a phone number and an access code for you. Give that number and access code to your attendees and you're ready to start hosting conference calls. FreeConferenceCall.com does offer some paid upgrades like custom greetings and hold music, but the core service is completely free.
Google Calendar users who want to organize conference calls can put their FreeConferenceCall.com numbers and access codes into the invitations that they send out as Google Calendar events. Click here to learn how to create Google Calendar events and invite people to them.
Applications for Education
Skype and Google+ Hangouts can be great ways to host virtual meetings with parents. However, if the parents you're trying to invite to a virtual meeting don't have Skype or Google accounts, you have put up an obstacle to meeting. Dialing a phone number and entering an access code when prompted is a much easier way to get parents into a virtual meeting.