Aravis pointed me to Different Religions Week, which takes place from Friday, July 15 through Friday, July 22. The website says that the idea stems from the fact that "[r]eligiously motivated violence is at a troubling level in the world today — 9/11 and the Israeli-Palestinian conflict come first to mind. Different Religions Week aims to take a few small steps away from the widespread ignorance and intolerance that fuels such tragedy."
There are links to information about several "main" religions (including Baha'i, Earth-Based and Zoroastrianism) so you can know something more about them and learn where the nearest place of worship is. I would recommend checking out your local library's copy of How to Be a Perfect Stranger, so you know what to expect and how to act once you go.
What a great idea!