Have you read the contract? Do you realize that a lot of the things we do are actually against the terms of service?
http://www.wireless.att.com/learn/articles-resources/wireless-terms.jsp
"While most common uses for Internet browsing, email and intranet access are permitted by your data plan, there are certain uses that cause extreme network capacity issues and interference with the network and are therefore prohibited. Examples of prohibited uses include, without limitation, the following: (i) server devices or host computer applications, including, but not limited to, Web camera posts or broadcasts, automatic data feeds, automated machine-to-machine connections or peer-to-peer (P2P) file sharing; (ii) as a substitute or backup for private lines, wireline s or full-time or dedicated data connections; (iii) "auto-responders," "cancel-bots," or similar automated or manual routines which generate excessive amounts of net traffic, or which disrupt net user groups or email use by others;...
This means, by way of example only, that checking email, surfing the Internet, downloading legally acquired songs, and/or visiting corporate intranets is permitted, but downloading movies using P2P file sharing services, redirecting television signals for viewing on Personal Computers, web broadcasting, and/or for the operation of servers, telemetry devices and/or Supervisory Control and Data Acquisition devices is prohibited. Furthermore, plans (unless specifically designated for tethering usage) cannot be used for any applications that tether the device (through use of, including without limitation, connection kits, other phone/smartphone to computer accessories, BLUETOOTH® or any other wireless technology) to Personal Computers (including without limitation, laptops), or other equipment for any purpose. "