That specific model gives a possibilty of the universe having an ultimate horizon, but being infinitely vast in distance, which it just seems to settle some of the more intuition problems raised here. Perhaps I am the only one that thinks it is easier to see that image (linked to in post 188) than to trying to reckon in our imagination the possibilities of an infinite or finite euclidean plane. However, you question is even more interesting, because this nice intuitive picture does not come without its consequences! The particular model I suggested implies such wonderous things as that there exist triangles with less that 180 degrees, that pythagorean's theorem actually fails, and that there can be more than one parallel through a given point to a given line! And it even goes so far as to imply that the reason that we may not be so sure about these (or even may go as far as to believe they couldn't exist) are only the result of our vastly small size in our quite large universe. It is inspiring to think that as it was once widely thought the earth was flat, and is now known to be not-so, it is now widely thought that the universe is euclidean, and may later be known to be not-so!