Q: My Web conferencing program supports both telephone and Internet audio. Which is better?

A: You can't beat the audio clarity of a conventional landline connection (sometimes called PSTN or Public Switched Telephone Network), which should always be your first choice for one-to-one calls and collaborative sessions with just a few callers, such as sales and product-design meetings. Telephone audio is simpler to configure, too: participants either dial in to a meeting, or the conferencing program automatically calls them after they sign in. With two-way Internet (sometimes called VoIP or Voice over Internet Protocol) audio, by comparison, your attendees must have a handset connected to their PCs--not always a given--and sound quality can vary greatly depending on Net congestion.

The chief drawback to telephone audio? It's significantly more expensive. Using WebEx Meeting Center with VoIP, for instance, costs just 2 cents per minute, compared to 12 cents per minute with PSTN.

Generally, VoIP is the more affordable choice for larger meetings that don't require two-way voice communication, including online training sessions, earnings calls with financial analysts, press conferences, and company meetings. During these sessions, the presenter can broadcast Internet audio, and attendees can listen via their PC speakers. Because the audio isn't two-way, listeners don't need a headset, and if they have questions, they can enter them via keyboard.

Q: Which program is the best for videoconferencing?

A: You might think that because all Web conferencing applications support audioconferencing, they all offer video support, too. Wrong. Some vendors' apps don't offer videoconferencing at all. The reason? Businesses often consider video a gratuitous frill that hogs bandwidth and creates a distraction from the task at hand. After all, if you're staring at yourself on the screen, picking broccoli from your teeth, you're not paying attention to the PowerPoint presentation.

Convoq ASAP Pro, Macromedia Breeze, Raindance Meeting Center, and WebEx include videoconferencing; Microsoft Live Meeting and Citrix GoToMeeting don't.

Of the lot, WebEx offers the most comprehensive video offerings, including multipoint video (also known as The Brady Bunch effect), in which a meeting displays multiple video windows--a handy feature for sessions with, say, four participants. The other vendors provide point-to-point video with a maximum of two video windows. WebEx's default frame rate--15 frames per second (fps)--is higher than that of its competitors, too. Raindance, for instance, tops out at 6fps. The higher the frame rate, the smoother the video, provided you have the bandwidth to handle it.

Q: I need to set up a conference call with 100 participants. Can every Web conferencing application handle this? Do I need to switch to one of the better-known programs, such as Microsoft Live Meeting or WebEx Meeting Center?

A: Every Web conferencing vendor sells packages for big and small users. As a result, loyal users of Citrix GoToMeeting, Convoq ASAP Pro, or Raindance Meeting Edition--three respectable conferencing programs from smaller companies--don't have to switch to bigger names such as Live Meeting or WebEx to run larger meetings.

Not surprisingly, the larger the conference, the more it'll cost you. To conduct a 100-participant session in WebEx Meeting Center, for instance, you'll need to buy a large "meeting room" for $1,000 per month, plus audio charges.