Spherical geometry (the airplane example I used) is probably the easiest of the non-Euclideans to understand, simply because it's got a physical analogue, both for the triangle definition and for making it expand (blowing up a balloon - no point on the surface is the 'center', and in fact, to any observer embedded in the surface of the balloon, *they* are the center of expansion).

If *Flatland* is more your cup of tea than cosmology lectures, there's a guy named Rudy Rucker who has a fabulous book called 'The Fourth Dimension' - fairly sure there's not an equation in the book, and it's got illustrations that remind me of James Thurber.