I have what I would call a "reverse WiFi router" (I am not sure what their name is... ask a nerd). I needed it for my TiVo to connect to my WiFi network.
Anyway, it connects to a wireless WiFi network, and offers hardware Ethernet ports for devices. I connected my camera up to that, initially for setup. At the end of the setup, I entered all the info needed for the camera to start using WiFi, and (permanently) disconnected the wire.
Let me add, that if you have a friend with a Ethernet port, you could bring the camera over there, set it up including all the info for your WiFi network, and then bring it back home.