I replied to a post on other forum about this, but I think this forum is better for noting a wonderful tool for those of us who grade essays online. I've been using it for a couple of years. The tool is T.A. Toolbar, a shareware product that can be found at Grading Essays is Better than Ever. I like it because I can grade an essay using a variety of buttons that insert comments automatically. It also has a holistic grading mechanism, plagiary detection, and can be customized to do whatever you need it to. Most of the comments it inserts into students' papers, by the way, have hyperlinks embedded in them, so if the student needs more information about a given error and how to fix it (such as comma splice or subject-verb agreement) they just click it and go. It's really quite brilliant.
Yes, I teach composition, literature, and creative writing courses at a community college.
I have been using eMarking Assistant which allows you to easily insert and modifiy stored comments into the paper or into the margin. You can easily create and save comments for future use.
The software is avaialble from www.baker-evans.com/emarking-assistant and there are screen movies and a 30 day trial.