Side note: Radiolab has a fascinating episode devoted to the phenomena of earworms. Definitely worth the listen. From wikipedia: Earworm . . . is a portion of a song or other music that repeats compulsively within one's mind, put colloquially as "music being stuck in one's head."
Did you know that through the Google Chrome browser, you can search by image instead of words? I gave it a whirl with an image of one of my nutstash jars and the search engine returned accurate information, as well as other visually similar (color scheme, composition) images. I can see a lot of potential here for designers, researchers, spies, and otherwise curious folks.
|a screen shot from the results of my image search in Google Chrome
What about a search by smell? Ripe with possibility.