Video by Mashable.
Zite creates a constantly evolving magazine based on both what you read and what you don't read in a manner similar to how Amazon recommends content.
Zite pulls in stories from your Twitter feed, if you wish, or your Google Reader account. Neither are necessary. You can also choose from hundreds of topics you're interested in or start with the plain-vanilla version of the magazine. That also is not required. Every story comes with thumbs up and thumbs down icons and a button to request more of that kind of story.
Zite is a free download from the iTunes App Store.