If one does a little study on the various ports used on a computer, you will find that the serial and USB are the ones that are used mostly for a slew of purposes such as communication, storage and so on and so forth.
Now since there are mostly only two serial (among other!) ports on any computer as opposed to several USB ports, some folks can use a docking station to add serial, parallel, PS/2, networking and Ethernet ports. Such a device can only be described as handy to have around! All you have to do to use it is use one of those many USB ports on your computer to hook it up with, and then you can go about your business.
If you are just looking for additional serial ports, then a USB serial adapter that ranges from providing one with 2 to 16 serial ports to use for their printers, modems, PDAs and digital cameras, and that too, in no time.
And while this can be an excellent option, it is important to ensure that the USB RS232 type of serial port is opted for, as the RS422 option is only used for PCs in industrial settings.
All in all, one doesn’t have put with the current deficiency of having just two serial ports by using these devices that are easily available.