find out what program has focus on os x
dave @ [ bahamas10 :: (Darwin) ] ~ $ osascript -e 'tell application "System Events"' -e 'processes whose frontmost is true' -e 'end'
application process Terminal
dave @ [ bahamas10 :: (Darwin) ] ~ $ sleep 2; osascript -e 'tell application "System Events"' -e 'processes whose frontmost is true' -e 'end'
application process Google Chrome