Just came across this – Drupal Gardens – http://www.drupalgardens.com/
Like Ning, but using Drupal. More like WordPress.com really, but using Drupal.
Many people have a free website for their personal blog or business. Generally they opt for WordPress.com, Blogspot.com, Google Sites or just make do with a Facebook page these days.
Drupal is an open source content management system that is very popular amongst web developers as it is easy to install, easy to learn and highly configurable. Like WordPress.org, you can bolt on modules (like plugins, add-ons etc) to enhance the site. If installed on your own domain it is a very powerful CMS.
With Drupal Gardens there is a choice of themes, all the usual Drupal features – pages, stories, forum, plus gallery and comments. At the moment you cannot install extra modules. It seems a good place to build a free site, if you are into that sort of thing. I set up an experimental blog here: http://howtoloseweight.drupalgardens.com/
It took me about 30 minutes to set that up, although most of the time was spent writing the first blog post (and yes, I know that it has not been proof read and is full of grammatical errors). In fact, I wrote a blog post, then realised that it should have been a page, so made a page, then deleted the blog post / story, then changed the URL/permalink to the page, then set it to show in full on the front page. Also deleted all the example items that are installed when you set up the Drupal Garden site.
If you are looking to build a community site, then I think that Drupal Gardens is a good option. The comments are better than Blogspot, the forum is better than comments alone, it has some pretty stylish features, such as flashy looking featured items.
As you can see, what I just created is pretty bare, but there is potential there for a good community, and since Ning is now closed to free accounts, Drupal Gardens could fill that vacuum better than WordPress, Blogspot or Facebook.