Digg...

... is kind of like StumbleUpon, with a human algorithm. It’s an interesting way to explore the Web. Rather than trying to exhaustively search for interesting or useful fragments, the Digg community helps each other, like a team of amateur archaeologists, and the result is a more holistic snapshot of what’s out there. People tag ("digg") items and you, the user, determine what diggs to view and how, as well as what you want to add to the mix. As with any good 2.0 site, it has a "clique feature": it can be limited to hand-picked friends. But doesn't have to be.

The interface is simple and easy to navigate. Main categories of excavated diggs are: news, videos, images, and podcasts. There is also a sub-menu of categories (which themselves have subcategories) under each of these. There is a lot of ability to customize, particularly under a settings tab (customize > settings), which allows you to filter topics, to pinpoint what you want to be viewing. Just one other useful feature is the ability to RSS specific search terms. Digg could be used for serious research, as well as leisure or virtual socializing. There's a lot to the service, and a lot more to be found through it.

But here's my favorite bit: a set of experimental visualizations, showing the activity of the community. [WARNING: may distract from homework.]