Flubaroo is a tool that I've used for years for to help me use my time more efficiently. Flubaroo is a script that you can use in Google Spreadsheets to have your multiple choice and short answer quizzes graded for you with just a couple of clicks on your part. The latest version of Flubaroo can even be used to email grades to your students.
Applications for Education
If your school uses Google Apps for Education, when you have students take quizzes that you've created through Google Forms, have your students sign into their accounts before taking the quiz. That way you will capture their email addresses and be able to quickly email grades to them after you have run the Flubaroo script to grade the quiz. If your school doesn't use Google Apps for Education you can still require email addresses by making "email address" a required question on the quizzes you create in Google Forms.
I'll be covering a lot of topics like this one and many more in my December PracticalEdTech.com course, How To Use Google Drive In School.