Can I make a shortcut or Automator action to toggle hard drive sleep?

[thermarest]

Problem I'm trying to solve: when I have an external FW drive attached, it spins down per the Energy Saver prefs check box and I find it irritating and disruptive when the whole system freezes while the HD spins back up. (As we all know, OS X waits for the drive to spin up often even if the current operation doesn't actually need anything from the drive). So, sometimes I uncheck "spin down hard drive." Then I forget to put it back, and my drive spins all night and all morning.

So, looking for a quick way to toggle this from desktop or the dock. Any ideas?

I just tried to make an automator action, but it didn't work. I've never really used Automator so rather than trouble shoot w/o much knowledge, I thought I'd ask for suggestions.