Applescript for Dismissing all Growl notifications.

GrowlDismissAll.scpt

# Dismiss all Growl notifications.
#
# If you're using this snippet with alfred and the power-pack
#  make sure to remove the default text alfred puts in there
#  aka "on alfred_script(q)" & "end alfred_script". You could
#  just paste the script as is.

tell application "System Events"
	set isRunning to (count of (every process whose bundle identifier is "com.Growl.GrowlHelperApp")) > 0
end tell

if isRunning then
	tell application id "com.Growl.GrowlHelperApp"
		delay 2
		close all notifications
	end tell
end if