37 signals shows off the new “Smart” pasting at The New Yorker site. When you copy something to the clipboard, the URL of the article, and a “read more” link are appended to the excerpt.
In general I like the idea of having this option, but I would prefer to be able to permanently disable the feature if it’s causing me problems.
With such sites seeking to monetize everything they can, I think we’ll see more features like this: I would expect, sadly, that they’ll be used more for copy-protection purposes than to help users share content.