FeedFlare by Feedburner

Feedburner introduced a new feature called FeedFlare. FeedFlare allows publishers to give their subscribers easy ways to email, tag, share, and act on the content of their feed by integrating web services such as del.icio.us, technorati, creative commonts, email into the feed.

When you choose to enable one or more services, FeedFlare will include a footer at the bottom of each content item on your feed. Services offered are:

Email this - Send a link to your item to someone via email.
Email author - Allow subscribers to email you directly. (If there is no email address in your feed, this will be hidden.)
Technorati Cosmos - Display the number of links to your item from blogs, as measured by Technorati. (If there are no links, this will be hidden.)
Del.icio.us tags - 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.
Count comments - Lists the number of comments posted to an item (for WordPress blogs only).
Creative Commons - Displays the Creative Commons license that you may have applied to your feed (or to individual content items).

To activate this new service, log into feedburner, and the FeedFlare service is located under the “Optimize” tab. Soon, Feedburner will also provide an API where publishers could tie FeedFlare into the originating web site content.

I enabled FeedFlare on my feed.