I'm often wary of any software that promises a shortcut from learning. CSS Hat offers a way to go straight from Photoshop layer style to CSS3 markup. This would be a huge timesaver and, assuming the code is streamlined, quite efficient. My concern comes with making sure you know the purpose of the code being generated first. That way you can always make subtle edits as need be. So, assuming you're comfortable with the markup for text-shadow and its ilk, dive right in!