The drone itself acts as a router, thats why it can't connect to another router like a wrt54g. With factory software is can't function as a client of another router, but routers can be reconfigured to relay the drones signal and extend the range. The drone emits a standard wifi signal for clients to connect to, so you have to configure your router to act as the client. With the wrt54g routers, you can use this firmware for the router:
its called tomato, once you install that and reboot the router you configure it as a relay point rather than a router. You will use the setting from the drones wifi signal when you configure the router/relay. Here is a demo with two routers connecting to each other, but in our case one of the routers would be the drone:
http://www.howtogeek.com/104007/how-to- … d-routers/
The router acting as a relay for the drone should considerably extend the range, but only in the vicinity of the router. Netgear makes a out of the box wifi extender if you don't want to diy. I have connected multiple devices to the drone simultaneously and its no different than any other non encrypted network.