Here is a video of John Maeda, the Associate Director of Research for MIT’s Media Lab, at the last TED conference in March 2007 discussing simplicity:
Last year I read and thoroughly enjoyed Maeda’s extremely short (~120 pages) book The Laws of Simplicity. I’d recommend it to anyone who does any kind of design. While designing with simplicity in mind may seem like common sense, I think sometimes we need a reminder and Maeda’s self-referential approach to discussing simplicity is a good one.