Brian tried to do a 6 person (I was one of those involved) 2 continent Skype conference to plan a Podcastercon. One obvious catch to this is that the originator needs to be on a very fast connection since he seems to be acting as a hub for the conference. The other is that if one person has a bad connection, all suffer.
The short of it is that we ended up on a conventional phone conference system with a lot of us using SkypeOut (in particular Cameron Reilly in Australia).
We could have moved over to text conferencing, but the Mac version of Skype doesn’t yet support multiple person text conferencing. That’s in Skype for other platforms so it should be coming to the Mac version soon. Half of us were (are) using Macs.

Jeff De Cagna pitches using Open Space Technology, which isn’t so much technology as a process for self-organizing at a conference.