What is a docking station?
Docking station also called port replicators provide a simpified way of "plugging-in" a notebbok to common computer peripherals, such as printer, monitor, mouse, speaker, microphone, card reader, ethernet network, keyboards, etc.  It also eliminates the clutter of cables connecting to your computer as it requires only a single USB cable.

USB Docking Station is also unique expansion unit specially designed to accompany notebook or desktop computers that have extra connectivity demands.

The use of a docking station quickly enables a notbook computer to become a subsitute for a desktop computer without sacrificing the mobile computing functionality of the machine.

There are a lot of USB docking stations with varies combination of external ports, basically make up of USB 2.0 port, VGA port, DVI port, Audio/Mic port, 10/100 ethernet port, parallel port and serial port.  Price range from USD 50 to USD 220.  You do have a choice to select the right docking station for your need and within your budget.