This is where you can go to find the history of the NDR and find out where there are events in your area.
Also interesting information, and a discussion of the tension between the National Day of Reason and the National Day of Prayer.
Unfortunately there are no event scheduled within a reasonable drive from my home. So I'm observing the day by writing this blog, and by wearing my "America: It's not a Religion Thing, It's a Freedom Thing!" t-shirt. And maybe I'll visit the library :).