Many times, the easiest way to let participants talk to presenters is to open up a phone conference line in parallel with your Web-delivered presentation. Implementing a parallel phone conference adds another degree of difficulty to the project because it means synchronizing two flows of information. It also forces the participants and the speaker to control telephone sets and computers at the same time. But it's an easy approach to set up; most telephone systems already have teleconferencing capabilities.
If you want the speaker to be able to see the attendees, you will have to install digital cameras and microphones on your attendees' computers. This may seem like an exorbitant expense, and indeed it usually is, because it requires a dedicated monitor for each participant at the broadcast point as well as software that can convey two-way video and audio streams for each person (which require more bandwidth).
But for many speakers, seeing and hearing the participants during the presentation is a very real requirement: It gives immediate feedback from the audience and helps simulate a more realistic environment. One compromise may be to adoppt this solution for a limited number of attendees.
Document annotation is only necessary when the content of the presentation demands that participant interaction goes beyond spoken questions. For example, the attendees may need to go back to a technical document and make notes to highlight their points. Luckily, most Web-based videoconferencing products offer whiteboards that speakers and attendees can use to share their thoughts.
If you're reluctant to invest in videoconferencing altogether, consider services such as the one offered by WebEx, which allows you to use its infrastructure for Internet-based presentations when you need to. This approach can be an excellent way to ease into videoconferencing and gauge how suitable it is for your business.
Web-enabled videoconferencing can remove many of the obstacles that make remotely managed presentations difficult and expensive to implement. The current solutions offer functionality that satisfy most requirements, but they cannot, and probably never will, be applicable to every situation. Nevertheless, the savings are often enough to offset the costs.