Disposal, pre-paid cell phones have long been used by criminals and terrorists. One can pay cash for the phone, use it a few times and then dispose of it. They are quite inexpensive and provide a secure means of communication that is not afforded by landlines or cell phones which require a contract service agreement. Lawmakers are now looking at ways to regulate the use of pre-paid cell phones. See "Lawmaker's crackdown on prepaid cell phones that abet criminal and terror suspects", Fox News.com, June 8, 2010. For an example of a prepaid cell phone see the link below.
T-Mobile Nokia 1208 Prepaid Cell Phone