Androfire

TDisplays links from del.icio.us, Technorati, Reddit, Digg and TailRank that is relevant to the current category of your blog. Eg: Your visitor browses the ?humor? category of your blog; the links will come from ?http://del.icio.us/tags/humor? and so on. This means that you do not have to change any code for each specific category.

WP-ExternalFeed

Displays links from del.icio.us, Technorati, Reddit, Digg and TailRank that is relevant to the current category of your blog

alaingg

Simple plugin that allows to include the images into your wordpress rss, rss2. 
The plugin use the post/page thumbnail or the firt attached image to the post/page gallery. viste the <a href="http://web-argument.com/2008/11/09/wp-rss-images-wordpress-plugin/" rel="nofollow ugc">plugin page</a> for details.

WP-ExternalFeed vs WP RSS Images