5. Calliflower: Iotum’s Calliflower service illustrates how IP technology lets conference calling evolve into something even more useful, though the additional capabilities may not come free. Like the above services, Calliflower allows users to create conferences immediately upon registering. After entering the call’s subject, agenda, date and time in the easy-to-use Web interface, customers can specify participants who will receive emailed invitations to join. The invitations provide dial-in numbers (currently available in Minnesota and France) and individual PINs for each participant. The PINs provide security by ensuring that only invitees can join. Participants can also call in over the Internet from their PCs via Sitofono or TringMe.

The free service provides call recording and the ability for callers to “raise hands” to indicate that they want to ask questions. It also permits interactive text chat among participants and provides a basic call control “dashboard” for the organizer. But the capabilities that take Calliflower beyond conference calling to the logical next step of Web conferencing only come with the for-pay premium version, which starts at $50 per month. The main such feature is document sharing, though the premium service also allows multiple organizers and international dial-in numbers in 18 countries.

via 7 Ways to Make Free Conference Calls.