I have seen many exchanges over the past week or so where someone says "Digg this" and gets at least one reply of "How do I do that?" or "Why should I do that?" or "Is that important?"
Let me explain a bit about Digg and how you use it, why you should use it, and touch on some ways in which it's important.
Disclaimer: I do not work for a news aggregator, but I've used them before.
Digg is a little bit like our "Recommend" button here on Daily Kos, but for the whole internet. If there's a story, or a photo, or a blog entry, or in fact any other kind of web page that people find interesting, they share it with Digg, or with reddit, or StumbleUpon, or Technorati, or other news aggregators that aren't leaping to mind immediately.
Many people use these news aggregators to find interesting things to read. As I said, they are for sharing any kind of web page people find amusing or profound, so most of what's there isn't going to be political. This is both an opportunity (a story can reach readers who wouldn't have thought about politics otherwise) and a challenge (it will be an uphill battle to get an article with serious content recommended above the latest cute pet photo or internet comic).
How do you sign up?
Go to http://www.digg.com/... and give them your information. They do have a privacy policy like all other internet presences.
How do you use Digg?
When you see a story or article you like, you submit it at http://digg.com/....
When someone else has already done this, like for example creating a link to this Recommended diary about Gallup polling at Digg (the link at Digg), you follow that Digg link and click on "Digg it" on the left-hand side of the article.
I don't have any evidence that the MSM uses Digg to find new and interesting stories, but lots of internet-aware people do. If we can reach a few more people this way, it's definitely worth doing.