This amplifier with an analog voltage multiplier could be useful in a bench power supply:
Combining a high-side current-sense amplifier with an analog voltage multiplier, the MAX4211 can easily measure the power dissipated in a load. One multiplier input connects to the load voltage, and the other to an internal analog of the load current—that is, a proportional voltage produced by the internal current-sense amplifier. The multiplier output (VLIL) is then a voltage proportional to load power.
Thanks rsdio!