I teach students to adapt to various technologies, both as users and producers, to gain confidence as writers in many varied envrionments, whatever the technology. This includes teaching audience awareness, rhetorical stuation, voice, tone, and genre as we have before--but now, too, in new ways never before imagined. Now they need to learn rhetorical purpose in new contexts: blogging, livejournal, wikis, web design, and multimedia, to name only a few.
For example, I have students do an exercise where they write down how they feel about school so far (they are all freshman in their first semester). Then I have them rewrite this, but as an email to their best friend back home. They actually write the email and send it. Then they have to rewrite again, this time as a blog on FaceBook (or MySpace--but it doesn't work as well). Knowing that those from school--including teachers--may read this, their voice, tone, and rhetorical purpose changes again.