If things ever get really bad here, militias will come back into fashion again, just as they did before. There will be a time that they are needed.
I agree, a lot of the militas out there today are jokes, and some are even filled with nut jobs and fed provocateurs as well.
Its best to get to know your neighbors, but keep your OPSEC up, befriend them, if things ever get bad here, you're going to have to all band together, and you're going to need each other. Then you'll have your own neighborhood militia type things, but until then, stay the hell away from them.
Look into resilient communities.
http://globalguerrillas.typepad.com/globalguerrillas/2008/01/the-resilient-c.htmlGet to know your neighbors. Befriend them. Keep your OPSEC up.