Google Reader's homepage has been updated and it features a small feed reader with three categories: "news", "sports" and "popular". The iframe points to this page and I think Google Reader should offer a customizable version, so you can embed it in your site.
Google already offers a cool AJAX Feed API that can be used to display the most recent posts from one or more feeds, but Google Reader's interface is more user-friendly and it lets you read the posts without leaving the page.
Michael Wesch, Assistant Professor of Cultural Anthropology at Kansas State University, gave a talk at the Library of Congress about YouTube and its role in the participatory culture. He explains how one of his videos, Web 2.0 ... The Machine is Us/ing Us, became very popular in just a few days and how this popularity took him by surprise. The video was remixed, translated, it was the starting point for a conversation at a global level.
To find how people communicate on YouTube, Professor Wesch and his students studied YouTube and the way anonymity, interactivity, authenticity and popularity define it as a new medium for community.