The Google Operating System blog uncovers a few snippets of JavaScript which add features to Google Docs, like a document table of contents, a thesaurus, and encyclopedia. For example, to generate a table of contents using your document's headings, enter this into the address bar while your doc is open:
javascript:mr("TocSettings");
To get a dictionary, thesaurus, or encyclopedia lookup on words you've selected in your document, use: javascript:MC=NC();GC("dictionary");
for the Merriam Webster Online Dictionary; javascript:MC=NC();GC("thesaurus");
for the Merriam Webster's Online Thesaurus, and javascript:MC=NC();GC("encyclopedia");
for the Encyclopedia Brittanica. Intermittently I got some timeout errors using these features, but hopefully that will get resolved and they'll appear in the official Docs interface soon. Add a Table of Contents to Google Docs and More [Google Operating System via Google Blogoscoped]