If you are looking for unlimited conferencing you are probably looking for a web conferencing program, which will allow you to have either an unlimited number of meetings and/or an unlimited number of people available to join a meeting. Here are your options from some of the most popular online meeting programs

Gotomeeting: With this type of service you can have an unlimited number of meetings, each with a maximum 15 participants. You can also opt for the webinar option, which will allow you to have as many as 1,000 participants and an unlimited number of meetings.

Webex: Webex and Gotomeeting are the two most popular online meeting programs. Webex is very similar to its counterpart in that it also allows an unlimited number of meetings, except for 25 people per meeting. Rather than having a webinar, Cisco offers a "Cisco WebEx Training Center", which lets you connect with up to 1,000 participants.

Microsoft Live Meeting: Depending on which package you get, you can have up to 250 participants in a meeting or 1,250 participants in a meeting. You can have as many meeting as you want and rather than paying a monthly rate, you pay for every additional participant connection. Because Live Meeting charges you per user you have to see if the do the math yourself when you compare this service to others. If you're only going to have 5 or so participants at each meeting, you're probably better off with Live Meeting. If, however, you have around 25 participants, you may be better off with a service, which has a flat rate monthly fee.

Yugma: You can either get a free account or one of their pro accounts. You can use their free account for as many times as you want. Their pro accounts have a lot of more useful features. The amount of participants for each meeting is limited.

Dimdim: Has 3 products available. Their free version allows you to meet with up to 20 people for an unlimited number of times. Their pro version allows you to meet as many times as you want for 50 people, with additional features as well. Dimdim Enterprise allows you to meet with up to 1,000 people for as many times as you want. Dimdim Enterprise is essentially a webinar.

If you are interested in having an unlimited number of meetings, virtually all web conferencing solutions have this ability because you get paid per month, except with a service such as Microsoft's Live Meeting, in which you pay per person. Because having as many meeting as you want is not an uncommon trait you're going to want to see whether the program you are looking at fits your needs in terms of features and pricing (this is discussed more fully in Interactive Web Conferencing). Most of the popular online meeting companies also allow you to have a "meeting" with around 1,000 people, which is about as "unlimited" as you can get. Often times this is called a webinar. Keep in mind, however, that with hundreds of people it will be less of a typical web conference because there will be fewer audience interaction. Usually the audience will interact by typing in messages to be received by the host or participating in polls. Usually, the maximum amount of people allowed in standard web conferencing products is more than adequate because it is around 20 people.

Of course, you can also take part in a conference call using a free VoIP such as Skype. It is unlimited because it is free. But it also only works for 5 people. You can also make use of a traditional conference call over the phone and pay for it with a flat rate fee or a pay as you go type of plan.