One of the best things I did this semester was giving my students quizzes via Google Docs. My Composition I students are given weekly grammar quizzes during the first half of the semester and I used to have them send answers back via email. This has become time-consuming and burdensome over time. This semester, I began giving them quizzes via Google Docs and added conditional formatting so they could be graded as students submitted answers.
Google Docs exports student answers from the form to a spreadsheet. If you add conditional formatting, you can make the spreadsheet grade it for you. I put wrong answers in yellow, so all I have to do with each student is see how many yellows they had. This has really helped a lot.