Academic Earth is a site that debuted in January of this year with the purpose of assembling high quality videos and entire video courses from the most prestigious universities in the United States. Visitors to Academic Earth will find lectures and courses from Yale, MIT, Berkeley, Harvard, Princeton, and Stanford. You can search for lectures and courses by topic, popularity, professor, or by university.
Periodic Table Tetris could be a fun and engaging way to learn the periodic table. I wish this game had been around when I was a high school student having to memorize the periodic table.