I wish the OS provided us such a hook. However, I've been using applescript to do this. I don't know who originally wrote this code snippet, but I think I picked it up over on macosxhints: do shell script "system_profiler SPAirPortDataType|awk -F\": \" '/Current Wireless Network/{print $2}' -- this will return you the SSID which you can use to detect your home or other network. I use it to mount volumes and run backups when I get home and to put away some elements of my movie collection when my work SSID is detected ;-)