A nifty feature of Google Docs is the research options. Right click on a word and you can choose to define the word over in the side of the document. This is a great excuse to get students to start looking up words they do not know. Share documents with students and ask them to find x words they do not know and use the define feature in Google Docs. After a few times of using this assignment, students should be in the habit of simply right clicking and looking up words rather than just skipping them.