Oh neat topic!
I posted this kind of related as it is my fantasy for brainz
Tag videos with apparel in ApparelBrainz. Tag plants with plants from PlantBrainz. Tag Antiques with items in AntiqueBrainz?? And not just music videos. Tag movies that are stored in MovieBrainz!
Items in each brainz would likely already be described as I desired through various relationships… then just tag videos with them. I like this topic. Need brainz for everything! All interlinked! Interlinked Brainz
Also did anyone suggest CarBrainz yet? I feel like that would be super popular. I’m not a car nut myself, but there are so many of them. Track cars, and after market parts? Make a collection of your car and it’s modifications.
Oh, and PlantBrainz should have a site to go with it, HarvestBrainz. Instead of listening history you track your gardens harvest history 
That way I can learn what varieties of veggies grow best in my garden!