digg.com - I was introduced to this site recently and it makes me reflect the extent to which the democratization of media content has taken place in the web2.0 space.Here' what digg does:

Digg is a technology news website that combines social bookmarking, blogging, RSS, and non-hierarchical editorial control. With digg, users submit stories for review, but rather than allow an editor to decide which stories go on the homepage, the users do.
How to promote stories to the homepage

Once a story is submitted by a user it is instantly posted in the digg area queue. This is a temporary holding place where stories wait to be promoted to the homepage. To help promote stories to the homepage, simply visit the digg area and digg stories you think are cool. Once a story has received enough diggs, it is instantly promoted. Should the story not receive enough diggs, or is reported, it eventually falls out of the digg area queue. Digg works because a large group of people actively promote good stories to the homepage. Since this site’s content is user-driven, it is up to YOU to contribute.

At the outset, it definitely looks like delicious / technorati popular tags with the exception that a user can submit a page so as to check its popularity index. It also gives a nice medium for youngish (considering these days, school kids are starting firms too) startups to spread the word about their service