bartman's network config

in /etc/network/interfaces ...

#auto wlan0
allow-hotplug wlan0
mapping wlan0
        script /etc/network/which-wlan0
        # the which-wlan0
        map essid=air.jukie.net key=on wifi-air
        map essid=xjukie.net \
            ap=00:14:BF:AF:98:30 \
            chan=5 \
            key=off \
            wdhcp
        map essid=G1Tether   key=on wifi-G1Tether
        ....
        map essid=linux    key=on wifi-ols
        map best wdhcp

....

iface wdhcp inet dhcp
        pre-up    modprobe ipw2200

iface wifi-ols inet dhcp
        wpa-ssid linux
        wpa-psk linuxsymposium

iface wifi-G1Tether inet dhcp
        wireless-key1   s:XXXXXXXXX
        wireless-mode   ad-hoc
        post-up         ifconfig wlan0 mtu 500

iface wifi-air inet dhcp
        wpa-ssid air.jukie.net
        wpa-psk XXXXXXXXX