Look Up Words, Search Images
The Google Docs crew made their first stop on its "Apps to School" tour, on which they stop at colleges across the U.S. and hang out with students, show off how they can use Google Docs for their class assignments, and see how studnets are already using it. They hung with some students at the University of Southern California. They also announced some new features that should help students do just that.
First off , you highlight a word and look up the definition/synonyms with Merriam-Webster's Collegiate Dictionary. This feature is located under the Tools menu in Google Docs in the same area as word count and spell check.
Also in the "Look up Word" section, you can find a similar feature that will let you look something up in Encyclopedia Britannica. I wouldn't mind seeing a Wikipedia option here as well, despite the question of accuracy on topics at any given time. It is understandable that they would leave such a feature off, when they're gearing these features toward students, but I would find it a useful feature.
Another convenient feature they added was the ability to do a Google Image Search from within Google Docs. Just go to Tools>Search the web for word...
As I find myself using Google Docs more and more, I am glad to see the addition of these features and look forward to more additions in the future.