I was sent over to Wordnik.com yesterday and all productive plans I had were immediately dashed and replaced with “let’s see what it says about this word…”
Wordnik’s purpose is to display all working knowledge, centered around the definition, etymology, and usage examples, but also providing information such as statistics and associated images, of just about any word in English your heart can dream of (1.7 million in total, according to the site). Users (registration required) can make contributions to any word they see on the site, such as related words and regional usage.
It does use licensed dictionaries and referenced works as the basis for its definitions and some usage examples. However, the success of the endeavor and where its usefulness as a tool for everyone and not just language researchers is that it incorporates recent Twitter messages as “usage examples” and can become another search tool to reflect and expand the common vocabulary we English speakers throughout the world are employing, which changes minute by minute each day.