Or maybe it is only available for WordPress . com sites?
It puts not only a link after comments to be notified of new comments on that post, but also includes a simple check box to be notified of new posts. I can't see how to post a screen shot here, so here is a link to a .com blog that has what I would like. (Look at the bottom of the comment form.) Is there a plugin that does this for our self-hosted sites?