I've been doing this through examiner.com since 2009 and while in theory the sky's the limit in terms of what one can earn, it's difficult to make more than lunch money. The calculation goes that to make $100,000 a year at a penny a page view one only needs to land 10 million page views. Piece-o-cake, right?
There is a thrill in having the opportunity to write News, getting articles into the stream of content which appears on Google News and that ilk. That gap between an event and publishing the story is alluring, to be sure. No longer is this role reserved solely for official Journalists at big news outlets. Small organizations with an independent voice can spring up and take part in the news conversation.
http://theurbantwist.com/ - describes itself as "a daily digital magazine, revolutionizing the news by delivering real-time coverage, breaking news, analysis and opinion on the arts, fashion, dining, music, events, politics, sports and society in general." There are several links on the site where you apply to start writing. They have a stringent screening and training process which they say weeds out 80% of applicants.
http://examiner.com/ - Is a large news website begun in 2008 (or so) that has 10's of thousands of writers. Each writer has a title ("UFO Landings Examiner") that indicates the topic area they're supposed to be covering. Some are rather broad ("Environment Examiner") while others are pretty specific. Lots of the Examiners have an additional constraint of covering news in a given area ("San Jose Dog Pound Examiner"). The site has a lot of training material on what makes things newsworthy, the format of a proper news article, using social networks, etc. There isn't much editorial oversight and no attempt to prevent multiple people from covering the same story. I've been writing on the site (see the links in the sidebar) for a few years.
http://torquenews.com/ - Automotive journalism site with a small, select, staff of writers.