Digg-like functionality for WordPress?

I have been hunting for a strong Digg like implementation social story / link system. I've found a few options, but wanted to throw this into the community for some discussion of perhaps what you have seen as the strongest candidates for such a solution. Here are what I've found thus far:

http://wordpress.org/extend/plugins/buddypress-links/
https://github.com/goldenapples/recommended-links
http://prothemedesign.com/themes/nominate-for-wordpress/
• (dead-ish?) http://www.onfry.com/projects/voteitup/