This AppleScript when used in conjunction with DragonDictate for Mac will play/pause the current iTunes track.

itunes-play-pause.applescript

	try
		-- Specify the application will want to work on, in this case iTunes.
		tell application "iTunes"
			-- Get iTunes current state
			if player state is paused then
				-- If iTunes is paused, press play.
				play
				-- Get iTunes state if it doesn't match the first condition
			else if player state is playing then
				-- If iTunes is playing, press pause.
				pause
			end if
		end tell
	end try