Esther Schindler has written a long column on CIO.com discussing tips for "Running an Effective Teleconference or Virtual Meeting." I was one of the people interviewed and quoted in the article.
Esther covers a lot of ground, taking a look at telephone conferencing, video conferencing, and web conferencing. There are certainly commonalities between the communications methods and tips that apply to all three, but a meeting leader should be aware of the differences as well and make an effort to work with and within the capabilities of the chosen medium.
It's worth a read, just to remind yourself of some common mistakes we all make that frustrate participants. You may pick up a pointer or two that you had overlooked in your own meetings.