What should I buy so I can use my laptop computer on long car trips?

A faculty member asked today about purchasing an adapter for her laptop computer that she can use in the car.

It is generally more expensive to buy a cigarette lighter to computer power adapter that is specific just to your laptop.

A better idea is to purchase an electrical "inverter" that will let you use any type of AC power supply in your car. An example is this $40 inverter from Wal-Mart. Using this device, you can charge your cell phone, laptop, or other electrical item using the same power supply you use at home. More expensive inverters are available that can power more electricity-hungry devices like refrigerators-- those are used by many truck drivers. To just charge a laptop, you should be able to get the least expensive inverter, which should cost you less than $50.