In the spirit of preserving spirituality as a private concern that each American has the right to create for herself or himself, here is a great article from Salon magazine (you can read it free after watching an ad). An excerpt:
I believe in the indomitable human spirit and the amazing capacity we have for understanding the world; for love, joy and happiness. Science not only does not take away any of those things, it adds to the sum of human knowledge. When I look through my little telescope in my backyard at the planets, moon or Andromeda galaxy that is 2.9 million light-years away, I can enjoy the beauty of the night sky and appreciate it on an emotional level. Then I can think that the photons of light that are landing on my retina left 2.9 million years ago, when we were just barely bipedal hominids in Africa, and are just now arriving tonight. Boy, that's just awe-inspiring.
To me, that's what it means to be spiritual -- what makes your spine tingle. It's what gives you a sense of awe and wonder and transcendence. It doesn't matter to me if you call it God or the cosmos. We're all talking about the same thing, whether it's religious people or New Age spiritual people or Buddhists or scientists. We're all talking about having a sense of awe and wonder at something grander than ourselves.