They can be especially useful for producing newsletters. Newsletters are easiest to put together when their authors have streams of content coming into a single place. For example, if you're writing a newsletter to a community affected by a disaster, it's useful to collect and view newsfeeds from organizations active in that disaster. When you see an item that the newsletter community might be interested in, you can then include that item in the newsletter. To do this, simply collect the news (RSS) and event (iCAL) from all the individuals and groups who want to be featured in your newsletter.