If you want to do that _now_
you can already use one of the B.A.T.M.A.N. based Freifunk firmwares. Those are easy to get onto your commercial off the shelf router (just download and use the "firmware upgrade" feature) and work without any configuration.
Those will open 2 networks, one adhoc network connecting the nodes, the other one is a normal managed network you can connect to with your cellphone, laptop or whatever. What you get is a large switched network, so it's transparent for most uses. You don't need any special software on your end devices and it just works.