I finished reading Flatland by Edwin A. Abbot this weekend. It was really interesting! Um...yeah, I'm a geek. XD;; It's a story about a world with only two dimensions, hence the name. And...well, it really makes you think about how your perspective changes the way you see things. The two-dimensional characters couldn't imagine a third dimension--so there could be a fourth dimension out there that we just can't imagine! Just like we used to think the Earth was the center of the universe, we think that our dimension is the "real" one.
Oh, and people in the fourth dimension can see inside us. X3