Atheism, imo, can be whatever you want it to be, though I agree that getting a group of atheists together is akin to herding cats.
You complained that there are no athiest social activities for you to join, but I wonder if you're going at it backwards perhaps?
Why not just decide with your wife what kinds of activities you enjoy doing together - ones that don't have a belief system as their starting point - and see what you can find locally?
For example, if you want to take cooking lessons, you wouldn't show up at a Catholic Church and expect to find cooking lessons, would you? You'd find a place nearby that offers cooking lessons and sign up for the ones that interested you. Or if you wanted to take up hiking or camping, you wouldn't go to an Anglican Church to find people interested in hiking, you'd go to an outdoors shop and check out their notice boards or find an online group and see if there are local people who are interested in hiking or camping and would be willing to share their expertise over coffee, etc. If you're looking for a few friends to take up fitness activities, join a gym that has the kinds of classes that interest you (yoga, tai chi, kick boxing, etc).
I've made some lovely friends by going to cooking classes and crafting classes, and I have amazing friends via my place of work. Mr Scully has made some good friends through his professional background. We meet people who have a similar interest in pets and people in our neighbourhood. But I don't expect them to come looking for me... we go out with an open mind and open to meeting new people in any situation.
One of the big disservices that has been part-and-parcel of "belonging" to a high control group like the JWs, is that the group fosters an unrealistic expectation of the social milieu, where everyone in the group is automatically your friend as soon as you walk in the door. Real friendships are not like that. Real friendships grow and develop over time, and require attention and thoughtfulness to cultivate them, in addition to having common interests. The thing is, when you start with a belief system as the "common interest", you still have to deal with the diversity of personalities beyond that. It's why there's often nothing to talk about between former JWs and the JWs that they used to be acquainted with and socialized with in the past... the only things they had in common were the JW belief system and their geographic proximity.
You can also try to find a local Freethinkers group and go from there. http://nobeliefs.com/freethinkers.htm or http://www.infidels.org/search.html