[email and mailing lists] have a bottom-up approach
and require the
least effort.
I definitely agree with this assessment; it requires much less effort to
fire off an e-mail than to visit a website, possibly having to log in,
and then post content using some textfield...
many open and active wikis will greatly benefit from
this.
many blogs are beginning to adopt the mail-to-blog feature.
... but I'm not sure that this concept could be applied to wikis.
After all, a blog (for example) is quite static, and content there can
easily be added without regard to any previously created postings.
A wiki, however, is the exact opposite; it is mostly dependent upon that
very content which already exists (and has probably been created by
other users than yourself).
I can't really think of an easy, non-complicated way to turn this into a
mail-based "workflow".
Nevertheless, if you can come up with a convincing concept for this, I'd
be very interested to hear about it!
Just my two cents...
-- F.