Great idea. Signed up as whitebark - email arrived in two seconds to gmail account no problems there!
Constructive criticism - the text size when entering the registration form was too small. My eyes aren't bad, but some peoples certainly are! And as the poster above noted - the new window is not the best idea - it annoys some, and is just bad web etiquette IMHO.
Will continue poking around and note here what I find. Thanks!