Hybrid vehicles use two types of engines for power: a standard gasoline engine and an electric motor-assist, powered by a rechargeable battery pack. This combination is designed to produce higher gas mileage and lower emissions than vehicles powered solely by gasoline. Many small towns across the country have recently made the decision to purchase hybrids for their town vehicles, not only for the potential savings in fuel, but also to set an example.

The latest buzz in hybrid vehicles is the Plug-In Hybrid Electric Vehicle (PHEV). This is a hybrid vehicle with larger batteries that can be recharged by connecting a plug to an electric power source, such as a standard home outlet. Like other hybrids, it has both types of engines, but for the low-mileage trips typically required for municipal vehicles, the electric motor can provide most of the power needed between charges.

As of this writing, there are no commercially manufactured PHEVs on the market (the ones currently in use are retrofitted standard hybrids) but as demand grows, manufacturers will be under pressure to produce them for the market. The PHEV "Sprinter" van from Daimler-Chrysler is expected to demonstrate a 50% improvement in gas mileage and an all-electric range of 20 miles.

One word of caution: Electro-magnetic fields measured inside hybrid cars have raised questions about their possible long-term effects on human health.