To register for the Fall Century on 9/8 at its reduced rate of $25, you need to register by the end of Saturday, 9/1. You can do it with a letter posted by that day or on on-line at BikeReg (they tack on $2.80). The web page has that link, a form, and more. After 9/1, it goes up to $35.
Note that I’ll also be adding an approximately 40-mile option.