A number of folks commented today, so I'm sending this our to the Acoustic Meet-Up list but in the future I'll only send to those who ask to be involved, so if you're interested, just let me know and I'll include you.
We had a session this afternoon. Four guys: three guitars, one bass. A broad range of experience but it worked. About 2 1/2 hours in Mount Vernon. I will host another, but am not sure when. If anyone else want to do one, step up. Unlike with acoustics, I don't think we can have more than 3 guitars at a time, but going forward if we have more, we can switch off. There was also a good amount of back-and-forth on stuff: I learned how nice a diminished chord sounds on the bass.
For ease, if you're interested, send me your email and I'll assemble a list. Let me know if you want to be bcc:ed in the future. Otherwise everyone will be included by name.