The iPod may be popular, but it also poses such a major security risk for businesses that enterprises should seriously consider banning it and other portable storage devices, according to a study by research firm Gartner Inc.

The devices, using a Universal Serial Bus (USB) or FireWire (IEEE 1394), are risky because they could be used to introduce malicious code into a corporate network or steal corporate data, the Stamford, Conn.-based research company said in its report, "How to Tackle the Threat From Portable Storage Devices."