Create the following shell script called scheme:
#!/bin/sh
if [ "$SCHEME" == "scheme" ]; then unset SCHEME
fi
rob@entropy:~/bin$ ln -s scheme home rob@entropy:~/bin$ ln -s scheme oreilly
home,*,*,*)
INFO="IBSS net at Home" ESSID="HomeNet" MODE="Ad-Hoc" KEY="1234-5678-90" RATE="11M"
;;
oreilly,*,*,*)
INFO="Work"
ESSID="OReillyNet" MODE="Managed"
KEY="s:sHHHH"
IWCONFIG="power unicast" ;;
nocat,*,*,*)
INFO="NoCat Community net" ESSID="NoCat" MODE="Managed" ;;
any,*,*,*)
INFO="Default configuration" ESSID="ANY"
MODE="Managed"
;;
Now, when you want to change schemes quickly, just type home or any to instantly change all of your wireless and network settings. As an added bonus, typing scheme will show the current scheme. Keep in mind that sudo will prompt you for your password, as you will need to be root to change the scheme.