I am assuming you saw the iPhone 5 commercial where they showed the "Do not disturb" mode.
With most Motorola devices you can use the Smart Actions app, which is even better than the apple setting, because with this you can set it to go on silent at specific times the day... and much more than that. Currently I use it for sleeping and work, so at 11pm my phone is on silent, then at 7am it comes on til 8am.. and so on..
But the galaxy nexus isn't Motorola so I'm not entirely sure if you're able to get that specific app, though I would think there has to be more apps that do the exact same thing.
Anyone know of any off hand?