Nokia intend 'Good Things' to be free form, explaining in the FAQ that a 'Good Thing is anything cool you want to share with the world'. You can easily add your own Good Things to Ovi Maps: use a simple 'drag and drop' pin interaction to specify a location, then fill out the details, complete a CAPTCHA and your Good Thing is automatically added to Ovi Maps.
Showing Good Things in the local area.
Currently the 'Good Things' listed on Ovi Maps are a little thin on the ground. However, it is likely that Nokia will use this kind of functionality for the technology and location database it gained when it acquired Plazes early this summer.
Plazes is/was a social context sharing tool that combines a mixture of social network, geotagging and location sharing functionality to enable people to track and find people, places and activities in their day to day life. It's not hard to see how this might fit into Nokia's Social Location strategy.
It is likely we'll see a rapid evolution of this location sharing feature. While currently it is only available on the desktop version of Ovi Maps, it is only a matter of time before it is also available on the mobile version, either enabled via the Ovi SDK - apps on maps, or as a much needed enhancement to Ovi Maps integrated 'Places' Point of Information database.
Good Things: display a recently added 'Good Thing'.
Each 'Good Thing' has a unique URL associated with it, allowing you to share it with your friends. Following a link will open up the specified 'Good Thing' in the browser, with the map showing the appropriate location (example).
From the Good Things FAQ, it seems that Nokia will also be relying on users to remove 'bad' 'Good Things'. For every 'Good Thing' there is a 'report as inappropriate link', if two people report a 'Good Thing' as inappropriate then it will be automatically removed. Clearly this system will be open to abuse, but the mechanics of adding, editing and removing 'Good Things' will likely evolve over time.
Rafe Blandford