reBlog

reBlog by Eyebeam: "A reBlog facilitates the process of filtering and republishing relevant content from many RSS feeds. reBloggers subscribe to their favorite feeds, preview the content, and select their favorite posts. These posts are automatically published through their favorite blogging software. "

There is a short stack of live reblogs to read from. Clippings.reblog says "I was using an RSS reader called NetNewsWire which has a weblog interface and allowed me to post items of interest directly to this site. However I have recently started using reBlog by eyebeam which provides a web interface for RSS aggregation filtering and publishing via moveabletype. Reblog is a more efficient method that allows for better attribution of sources."

I'm quite fond of Bloglines Clip Blogs that lets you easily create a blog while reading feeds or in the wild with the Firefox Toolkit.