This is pretty nifty: You can generate, explore and edit mysterious and beautiful landscapes using the webcam on your computer. Make sure you're in a well-lit area, let your browser access the webcam, and then try pointing it around the room as you use standard controls to "walk around in" the unique spaces that blossom before your eyes.
The tool, called Reflection, is by Ian MacLarty, and it's both awesome and unsettling. Reminds me of being a kid, face pressed up close to peeling paint or aging carpet, imagining entire worlds inside the negative space. Of course, when I turned the webcam on at first, it was pointing at me, and I found myself wandering into a swollen-cheeked land where some cloud formation of my own face, eyes slowly blinking, constituted the sky.
Try it for yourself. It's free, simple and provokes the imagination.