It could be very convenient to use your cell phone as a modem, so you can take your laptop anywhere and connect to the Internet even when there is no Wi-Fi hotspot connection or cable available. It is also more secure than public Wi-Fi, as the Internet data transfer goes directly through your wireless carrier and private cell phone line. Phone companies have monthly plans and unlimited data plans that include this service.
Tethering, as this cell phone-as-modem option is also called, can be accessed freely using other options, but you may incur extra data transfer fees. However, not all cell phone models support tethering options.
You can connect your cell phone to your computer with a USB cable or via wireless Bluetooth. If you have a 3G cell phone, you can connect by Wi-Fi, and it will transfer data more quickly. While your phone is doubling as a modem, calls will go to your voicemail automatically. If you make a phone call, the data transfer to your computer will be interrupted.