There are some posts that seem interesting, and I want to get an email notification when answers are posted, even though I'm not the one who asked the question. How can I do that?
tag question has an Atom feed. You could use Feedburner to consume the feed and subscribe to the Feedburner feed via e-mail.
You could use RSS Feed for this.
You can take
http://stackoverflow.com/feeds for last 30 questions