Thanks to Dom for pointing this out to me.
Check out this screen-recording of a demo Flash Flex application called NoteTag.
The application uses Blogger and del.icio.us as a back-end for storage. Blogger is used to store objects and del.icio.us is used to store associations between them.
This is on the same meme as using your Gmail account as a virtual hard drive where the API is being used for something other than what it was intended for.
Good to see that people are starting to do this. This is relevant to me because the MetaWrap project is all about wrapping these kinds of API’s into an accessible registry and Meta-API. More about this later 🙂