Iam a big fan of public Wi-Fi hotspots and services such as Boingo, AT&T Wireless and BT Openzone, which enable itinerant laptop users to go online in airports, hotels and coffee shops. But sometimes a Wi-Fi service is unreliable or too many people are trying to use it, or there is no signal at all - such as during my train commute.
That is when I turn to a cellular data connection. There are three basic ways to get online using a laptop and a mobile phone network: using a laptop with an integrated cellular modem; hooking up or "tethering" a laptop to a smartphone; and using an external cellular modem or personal mobile hotspot device such as Novatel's MiFi.
