Today, affordable storage media comes in various form factors with a wide range of capacities. USB is the most popular PC interface, offering data transfer rates as high as 480 Mbps (version 2.0), with enough power to operate storage devices such as 2.5" hard-disk drives. The Fire Wire interface offers similar capabilities. A few vendors offer software that lets users synchronize their email and network folders with USB storage. This lets them access these data items from several different computers. The U3 industry consortium promotes a model that lets users run programs, such as a Firefox Web browser, directly from the USB storage device, so users can access these applications even on PCs that don't have these applications preinstalled. Similarly, commonly used live CD-ROMs let you boot a PC from an OS resident on the CD-ROM. In this new mobile computing model called portable storage-based personalization, users can personalize a computer by booting from the USB storage media. Users' portable storage devices act as a pocket hard drive.