Scoop.it is an online tool that allows you to create a public collection of articles from the web. All you do is define a topic (e.g. electronic textbooks) and whenever you see something related to that topic, you click on a little bookmarklet in your browser and the item is added to your Scoop.it page with a picture and a blurb. Click on the blurb and you are taken right to the original source. You can also create your own posts.
Your scoops can be embedded into your blog and tied into your social media accounts (Facebook, Twitter, etc.). Others can leave comments on your scoops and follow you via an rss feed. A great way to create a conversation about a topic of interest to a group.
Check it out here: http://www.scoop.it/