Fiat's Multiair System

Fiat has developed an interesting engine system for improving fuel economy. called Multiair. This is another type of variable valve timing and lift device. Fiat's trick is to use a hydraulic path from the cam to the valve, which goes through an electrically actuated valve. By modifying the fluid flow through the valve through the engine cycle, Fiat can implement variable valve timing and variable lift.

Here's a short video on the subject.