I'd like to be able to connect between two computers that exist on separate WiFi networks (things like Samba sharing, UPNP node control, etc. - basically, all the usual LAN things). The key thing is that the two WiFi routers are physically connected by an Ethernet cable, but the devices are physically too far apart to be connected on the same WiFi network. Both WiFi networks get their internet connection from one of the routers.
Is there some way of either unifying the network, so that everyone is connected together, or otherwise setting up a some sort of 'bridge' (I have no idea if this term is suitable) to connect the required machines up?