Cingular phones cause interference in computer speakers, car stereo speakers, and speaker phones.  This interference produces a sort of "galloping" sound.  This has been written about at PC World and Chron.com.  Cingular uses GSM technology on its network (as opposed to CDMA, which is used by Verizon), and this causes interference with unshielded electronics such as speakers.  Speaker cables essentially act as antennas, which makes the problem even worse.  So the next time you hear some buzzing or other weird noise coming from speakers, ask around if anyone has a Cingular/AT&T cell phone. #technology