But first, what is it? SnapGrades is an Online "Web-based" application that lets teachers create and maintain an Online gradebook that is customizable to meet their own personal grading needs. There's a little work involved: you have to first input your students' names, set up the classes or subjects you teach, and that's about it. The best part is: it's free. The site constantly updates, so there's no "save" button required, which is a huge headache reducer.
There is a paid membership available. $49.99 for the year buys you a single user license. For about the price of one Mocha Frappuccino per month, you can give parents and students Web access to grades 24/7. You also get the ability to send Email alerts, Spanish translation, administrative access, and report cards school-wide. A word of caution: bear in mind that when you give parents and students Web access to their grades, you're placing an expectation upon yourself that you will be current with your gradebook maintenance (which may or may not be realistic). For example, there are times when you may want to factor in classroom participation points (which can have a positive or negative impact on a your students' grades) and you may not wish to factor in those points until you get closer to your grading deadline.
You had me at iPhone. The idea that I can add an assignment, input students' scores, and have it automatically update my gradebook, all from my iPhone! is truly remarkable. Another notable feature is the ability to weight assignments in a straightforward way. For example, in my Math class, I choose to make quizzes worth one assignment; exams are worth two assignments; midterm exams are worth three assignments, etc...
If you aren't committed to a gradebook solution, or are unhappy with your current one, do yourself a favor and try it. Visit http://www.snapgrades.net.