Google announced recently that they will be updating their Spell Checker in Google Docs. Google describes the update this way:
The neat thing about that system is that it’s adaptive: our suggestions get smarter and smarter based on the words Googlebot sees as it explores the web.What's even cooler about having an adaptive Spell Checker is that it's also contextual. If you look closely at the image above you'll see that I've used the wrong form of "meat" and it suggested the correct one to me. I'm not sure how crazy you can misspell things, but it is a good option for many students.
The other very cool point is that it looks like to Google Team is working to integrate it into the Chrome Web Browser which would help in all parts of using the web. You can find some more information here at Lifehacker - Google's New Spell Check is Crazy Awesome.