Send a link to your item to someone via email.
Allow subscribers to email you directly. (If there is no email address in your feed, this will be hidden.)
Display the number of links to your item from blogs, as measured by Technorati. (If there are no links, this will be hidden.)
Lists del.icio.us tags for an item. (If there are no tags, this will be hidden.)
Save to del.icio.us
Allows subscribers to bookmark the item with del.icio.us.
Lists the number of comments posted to an item (for WordPress blogs only).
Displays the Creative Commons license that you may have applied to your feed (or to individual content items).
I’ve turned them all on, save the Email Author feature, for obvious reasons. I may turn off the comment counter as I think it’ll cause NetNewsWire to register a change, and therefore mark it as new again. All this for free!