I've just upgraded my Google Search app on my Nexus 7 and it has a few interesting new features.
One caught my eye in particular; with Google Voice you can now say; "What's this song?" and Google will attempt to find the song you/it can currently hear.
Actually, Google's been able to do something like this since 2006 - even on TV programs - as this BBC report features. This is just the first time, I'm aware of, that the technology has been given to searchers.