This WordPress 2.0 plug-in will allow you to let your users subscribe to your site with their email address. When you post a new article, it will automatically notify them of the new post. This has only been tested on WordPress 2.x.
There are many forums on the Internet, and one of the best ways to promote yours is to get your posts noticed! By submitting your threads to update services, your exposure potential is unlimited!
Download here.