I love the above definition of minimalism because it really captures that it's not just about having less stuff or living a simpler life. Minimalism is about getting rid of what you don't need and don't love in your life and focusing on what remains.
I've started following The Minimalists and started following a local minimalist group on facebook. I just really loved this video. It does a great job at emphasising the peace found in minimalistic living:
You can learn more from these guys at theminimalists.com.