The NY Times (my favorite paper, I guess) has an article about a proposed Muslim center at the foot of the new World Trade Center complex. I'm truly torn myself about the idea. On the one hand, terrorists might feel like they triumphed by replacing the WTC with a mosque. On the other hand, it would demonstrate America's tolerance.
My solution: put two mosques there, little tiny ones, one Sunni and one Shiite. I mean really tiny, like a good-sized closet. And put two tiny churches there as well, one Catholic and one Presbyterian. Add temples for Judaism, Buddhism, Hinduism, and Bahá'í. Make room for a few more, and even a couple of spaces that could rotate through the smaller religions on a monthly basis.
Put these mosques, churches, and temples in a circular courtyard, facing each other, with a shared entrance. Put in big clear windows on the courtyard side, so worshippers can see the people of other religions worshipping, too.
And on 11 September each year, let the WTC religious groups join together in offering each other and all passersby blessings and a modest free breakfast.