Beyond keyword search

We need more than keyword search on our computers and networks. The trouble with plain keyword search is that you might know what you're looking for, but not how it is filed, what it is called or how it is spelled. All of these can throw off search results enough that you miss your mark. Or you might be looking for something that's totally non-verbal, like a picture, a piece of music or a dance. How do you search for a painting without knowing where it's from, who painted it or what it's called?

Mokalus of Borg

PS - We need the audio and visual equivalents of keyword search.
PPS - Which might be like searching by humming or sketching.