I have really enjoyed reading through all the wonderful, insightful posts in this thread, and I just wanted to let you all know that, and thank you for contributing. Nipith, I particularly found your emphasis on masculinity as a primary theme of the film to be illuminating, and realize that this is an important element in viewers' powerful responses to the movie. It's true that both Jack and Ennis idealize the life of the cowboy, and aspire to be successful cowboys themselves. One senses the mutual respect, as well as admiration, that the two men come to feel for one another, and this is very much tied into the masculine qualities in their personae.
Alec716, I thought you expressed beautifully how the mountain, in its very harshness, brought the boys together and fostered their love. This dichotomy between harshness and tenderness/sheltering is very poignant to me, and enhances the beauty of the story's themes immeasurably. And you're right to point out that the human world was ultimately much more unforgiving and cruel to who Ennis and Jack really were than the world of nature ever was. In fact, through the postcard of the mountain that Ennis cherishes, it is intimated that he longs to return to that harsh, austerely beautiful world, if ultimately only in spirit.
Great job, everyone.
Scott