TechCrunch and GigaOm have long posts about the functionality and the strategy. Here’s a video tutorial.
While not unique in its functionality, Ning appears to “democratize” social networking by allowing anybody to create their own network, as opposed to a network within a network (e.g., MySpace, Facebook).
There’s a built-in viral element (people in your network may create their own). The eventual “play” here is to create a “network” of thousands of micro-networks that then can support very targeted advertising.
But on the “consumer” side this is very interesting. If it is as easy to use as represented — and it does seem to be — you’ll have lots of people using this as an alternative to blogs, websites and wikis/groups or in conjunction with all.