When you think of portability many people believed that you would not be able to get the power and functionality as compared to a desktop system, today is not true. Desktops are the preferred computer because of the ability to add peripherals and the power are much more than a laptop, but today laptops are able to add peripherals and have the computer power and have the ability to snap into a docking station which emulates a desktop. That has now changed and laptops are becoming affordable, light weight, faster and the ability to add many peripherals via USB.
Laptop computers are great portable offices, and as technology increases and speeds of computers increase, we are seeing battery life also increase and provide longer usage time with out the need to be plugged in. An extra battery is always a wise purchase when buying a used laptop. The batteries on many systems only last for about 2 years so if you get more life out of the battery you are one of the lucky ones. Battery life varies with the efficiency of the processor, so check out battery life in any reviews you read. When looking at the weight of the laptop dont forget to add in the weight of the battery chargers...