There's an idea for that ...
We can't host the files for legal reasons, but maybe the OT cloud backend could serve as a tracker, pointing client machines to where to get the object, should they see it.
It would work like this - when you as a player visit a location where there are some custom objects, the engine would retrieve the positional info + object type (a hash code of it). If the user already has the object, it would be rendered directly, otherwise a bounding-box placeholder will show up, and the client can query the server for the locations of the model. These should be either torrents or direct http download sources provided by third parties.
Thus, to create a library, you could just set up a custom file server that's hosting the files. To place the objects you'd just provide such an OT-recognized model link and place it into the world; OT would automatically update the tracking db.
