> How about an integrated newsgroup+mailinglist+forum. If we had a
> two-way newsgroup+mailinglist integration, people could use it also
> as a forum, for example through gmail.google.com. But I don't use
> fora, so I probably talk nonsense.
I think Gmane has everything you're looking for (bidirectional
mail-to-news gateway, you can read and post via a web page, and quite
a few Haskell mailing lists are already archived there; see
http://dir.gmane.org/gmane.comp.lang.haskell.general, for instance).
I've hardly used it, though, so I can't tell whether it works well.