Email a friend a specific article, not necessarily the article itself
but rather the intro page, (i'm not sure what you call it) but the
page where you click, 'read full article'
-- maybe after the user sends the email to their friend, in like
a confirmation page type thing, suggest that they check back to see if
their friend posts a comment regarding the story they suggested for
them? This could build more dialogue within TPF and between users.
Enter zip code to get specific weather news (and maybe traffic/mass
transit alerts?)
Can you email a forgotten username and password?
Daily Reads?
Add the story that got the most hits per category to the users log
in page as suggested reading?