Using your smart phone as a modem allows you to access the Internet on your laptop or desktop via the mobile broadband connection on your phone. Most Smart Phones support this feature, although it is not widely-advertised by cell phone companies. This is because most carriers also offer mobile broadband plans that require a separate fee and use different hardware. Despite this, using your smart phone as a modem is a great choice, as long as you do not exceed the maximum bandwidth allowed by your carrier