The Japan Trend Shop, yes there is such a thing, has these trendy-designed toilet silencers - that's right, you read that correctly. These little guys were made to makes the noise of a toilet flushing to hide the - other noises - you might be making. You press it twice and the sound of a toilet flushing chimes for 25 seconds. Press it twice again, and the flushing stops.
Don't believe me? See it for yourself here.