Part of Barcamp News Innovation Philly is an open data hackathon.  I wanted to do a live visualization of something and I wanted to use canvas.  What I did is create a “Paint thrown against the wall” visualization of tweets tagged #bcniphilly.  The color of the tweet is specific for the user, the size of the circle is based on the length of the tweet and the location is based on the id (so it’s pretty random).  It will take a moment to load the most recent tweets and auto updates every five seconds.  I’ve only tested it in Chrome (so no promises that it will work in anything else)  Check it out!