This is an AppleScript that is used to change your network location. It can be assigned to a shortcut using Automator.

network_location.applescript

try
    set network_location to do shell script ("scselect | awk '{if ($1==\"*\") print $3}' | sed 's/[()]//g'")
on error
    display dialog "There was an error with the script."
end try

if network_location is "LocationA" then
    do shell script "scselect LocationB"
else if network_location is "LocationB" then
    do shell script "scselect LocationA"
end if