A watched pot may not boil any faster but could yelling at it help? According to researchers at the Georgia Institute of Technology it couldn't hurt. In a paper published in the journal Physics of Fluids the group shows that they can acheive a 17% increase in boiling efficiency by using an acoustic field to increase heat transfer. This increase in efficiency comes as a result of removing vapor bubbles from the heated surface. These bubbles form an insulating "vapor film" between the heated surface and the liquid - thus increasing the amount of energy it takes to bring the liquid to boil. The acoustic fields cause capillary waves on the bubbles causing them to detach from the surface.
The researchers explored this phenomenon in three different ways - "an air bubble on the underside of a horizontal surface, a single vapor bubble on the top side of a horizontal heated surface, and pool boiling from a horizontal heated surface. The researchers were able to isolate and identify the dominant forces involved in these acoustically forced motions by measuring the capillary waves induced on the bubbles, bubble motion, and heat transfer during boiling."
More information can be found at http://pof.aip.org/.