Google Hangout
I realized that one way to deal with the disparate geography is Google Hangout - basically a group skype. Since google+ has really good "circle" controls, I can add anyone into a "truenudist" circle and invite them in. I'm not sure if there's a group option that isn't dependent on a particular member starting it, but as a proof of concept, I've started one (same id: orbarebear). Send me your g+ id and I'll add you into the circle, invite you into the hangout and try to leave it running as much as I can even if I'm not here...
It looks like there's a limit of 10 people and I have to check in every 2 1/2 hours (https://support.google.com/hangouts/answer/1216376?hl=en&ref_topic=2944848), but if those who are interested add each other into their "truenudist" (or whatever they want to call it circle) and post when they're on and off, we might get to a point where there's always at least one hangout running...