So, at this blog we call this event "24-Hour Comic Day" 'cause it makes sense to us to use a hyphen and the singular "Comic" is less sloppy (and because that address was available on Blogger). www.24-hourcomic.blogspot.com
However, the official name is "24 Hour Comics Day." The official Web address is: www.24hourcomics.com
The official site has its own blog at: www.24hourcomics.com/blog
Us: hyphen and no "S."
Them: no hyphen and an "S."
Glad we got that cleared up.