How to Add "Notify Me" checkboxes after posts

A friend of ours with a WP.com blog has "Notify me of follow-up comments via email." and "Notify me of new posts via email." checkboxes under the comment/reply area on her single post pages.

My wife says we should have them too! lol

A good example of the friend's blog may be viewed at http://ruitfarm.wordpress.com/2010/0...rsimmon-twist/

After much reading I've figured out how to insert

"%comments-rss('linktext')% - Displays the comment feed link for a post, with linktext as the link text. "

in a post's footer, but NOT the "new posts" signup and definitely not with the checkboxes.

I'm thinking there must be a plugin at work but I can't figure it out. Our friend doesn't know how she's doing it -- she thinks it just came with her theme.

Thanks Jim