Fresh from its intro in New York this morning, here's a size comparison of Amazon's Kindle 2 e-reader. The purple rectangle in the illustration is the Kindle 2, the gray rectangle is the original Kindle. Both are compared to the size of an everyday soda can.
Notice the new Kindle is slightly taller (a half-inch) than its predecessor, but the most striking dimension: the ultra-thin 0.36" thickness of the thing, about the size of many of today's shrinking magazines and half the depth of the original Kindle. Look at it from the side, and it's almost invisible.