Bert Edens set up a Spider-Man listserver a few years ago. It went great for a while... all the Spidey-chat you could eat! Sadly, it faded out, but a bunch of fans from the list have just recently ressucitated it using the eGroups mailing list service.
The new list is called Spidey's Corner.
Editor's Note: This list is now defunct, reference removed.
Check the FAQ for more information.