Yes we did that for awhile in our town with friends, wore sunglasses ALWAYS at night. Always a good look for people to do doubletakes everywhere you go. They pass over you then like "WHOAH!....what?"
It worked great with about 5 people, but yes I do think there needs to be more people or something "bigger" in the scheme... I always wear my trench coat as well, and my hat that says "freak"....so I get good enough looks anyways.
Maybe some kind of scare tactic or something provoking others to wear them. Combine it with postergasm in various places, by putting up signs that warn of certain things like.....
SOLAR FLARES!
And have the signs warning of things like that, so the (insert federal safety agency here) suggests everyone keep sunglasses on for protection during the night at certain times. Make the posters look official, put them up around town on businesses...poles, whatever. THEEEEN get your group of however many people MORE THE BETTER and start walking with sunglasses, and if you feel gasmasks would add a good effect. I think the next night would see either a lot of people playing along, or at least wondering...
The public can be scared into anything if the gov. says it's true....
take the duct tape and plastic sheeting example...they said that would help in a nuclear attack.
EDIT: Made One...
