I've got a couple of nagging questions about wireless networks that i can't really find a definitive answer to I'm aware that a AirPort/Wi-Fi network will only operate at the 'lowest common denomiator' speed, i.e. if you have a b/g capable network and have all g speed devices but then add an older b device, the whole network will slow to accommodate that device and the networks' max. speed will be b. My first query is, does this happen only when the b device joins the network? I have an old iMac and iBook that use original AirPort (802.11 b). Could i set up my AirPort to create a b/g compatible network which would operate at 'g' speeds until these computers wake up and join the network, or would the speed be permanently at 'b' in case these computers wanted to join? I also have a Nintendo DS lite which I'd love to play via the Nintendo Wi-Fi connection, but the only security protocol it will work with is too low for the rest of my network. I wondered if i could use my current AirPort express to make a low security 'b' network for the older Macs + the DS, and then buy a new Wi-Fi router to serve a 'g' network for the newer Macs internet access + a Wii. Will two networks conflict much with each other, reducing the efficiency of both? Any advice or suggestions would be appreciated.