Ad Hoc vanner groups

Ok, maybe Ad Hoc is not the exact terminology I'm looking for. Never thought I'd be thinking about this, but after the last couple of Chicago area van shows, it looks like we have a number of As and other Earlies in the area. A few of us are thinking of getting together and hitting a couple of car shows and whatnot next year.

Definitely not doing a "club". Don't want rules or dues or politics or officers or head aches.

Given that we live in this high tech modern era, I'm boiling a few options down where we can simply get our butts at the same place at the same time without any miscommunication or drama.

First thought- Email. May not be checked frequently enough. May not want others to get your email address.
2nd - Facebook. Currently not on it. Don't know how many others are. Should be easy to setup and maintain some kind of "XYZ Vanner's" page.
3rd - Google Circles. Probably most appealing. You can narrow down who sees what to specific groups such as family, extended family, bowling friends, business, vanner friends, etc.
4th - Twitter. Don't really understand it. May be a bit annoying? Can you have an informative discussion with 6 to 12 people?

Thoughts or ideas?