Brad Neuberg has put together an educational Introduction to HTML 5 video that goes over many of the major aspects of this new standard, including:
* Web vector graphics with the Canvas tag and Scalable Vector Graphics (SVG)
* The Geolocation API
* HTML 5 Video
* The HTML 5 Database and Application Cache
* Web workers
If you don’t know what is HTML5 or what features it has, I strongly recommend you to see this introduction.