Handheld companions -- These devices are most often categorized as personal digital assistants, PC companions, and personal companions. Characteristics of this product category include the use of these devices as supplements to desktop or portable PCs. Applications often used on these devices include personal information managers (PIMs) as well as data collection and light data-creation capabilities. Smart phones -- This category includes the emerging enhanced super-portable cellular phones that enable both voice and data communications. Aside from devices consisting of cellular voice communications, these phones have the ability to access the Internet and store light calendaring and Rolodex data such as names, addresses, and phone numbers. In addition, smart phones will generate a new breed of software developers as vendors either work with existing handheld operating system providers or use proprietary operating systems. The OS providers will provide software-development kits to developers for application creation. International Data Corp. excludes the emerging deskside screenphones from this segment. Vertical application devices -- Primarily pen or keypad based, these devices are used with specific vertical applications in a variety of industries. Examples include route-delivery data collection for a vendor in the transportation industry or a physician accessing a patient's records in a hospital.