There was a time when choosing a cell phone meant deciding on what phone, the plan rate, and how long you were willing to commit yourself to use the service. This was usually 2 yrs, on the average, and most people hated it.
One of the things people hate most about those type of plans is, if you want to get a different phone, you also have to sign a new contract. For a long time, there were only a couple of providers who offered the pre-paid cell phone service. But now, virtually all the big name wireless providers offer some sort of pre-paid (pay as you go) service option!
