I recently discovered that one of my hometown papers, The New York Post, has an interesting little feature that you'd never notice because they call exactly zero attention to it—you have to stumble across it. Here's how it works:
Say you're on a story page reading about the recent Roy Halladay trade and you want to share the link with your friends along with a quoted passage from that article. You select and copy a passage, and when you paste it into your email client, here's the text you get:
So, on a day when Halladay moved closer to being a Phillie, Lee was on his way to Seattle, Lackey took a Red Sox physical and the Yankees' World Series MVP is headed to the Angels, the Bombers were winners.
Either way, I think it shows how you can offer more functionality, context, etc., to the user without demanding more of them and that might ultimately change their behavior in the future. It only takes one time for users to know the feature's there and in the future they can really speed up their interactions with the site.