200 Personal Content Experience: Managing Digital Life in the Mobile Age hidden from view. A layman is usually not interested in the technology that is involved in the operation of the personal content management system, taking them for granted. The usability and usefulness of the whole system is judged by the user based on the user interface, that is, the components of the system that the user interacts with. Therefore, the role of the user interface is not to be underestimated! There are numerous devices that are considered mobile, based on their battery life and the tasks they are designed for (see Chapter 2 for discussion on mobility and the classifi cation of mobile devices). Also, a mobile device should be small, lightweight, and fi t into the user’s hand or pocket, being easy to carry at all times. Such a device may also be worn in an arm or wrist band or carried on a neck strap or a belt holder. We concentrate on devices suitable for continuous and nomadic mobile use (Rosenberg 1998). The use of a device is considered con- tinuous if it can be operated while the user is actively moving (walking, running, or riding a bike, for instance). However, operating the device is not usually the primary task. On the contrary, in nomadic use situa- tions, the user may be temporarily stationary, such as sitting in a cafete- ria or standing at a bus stop. Using the device while sitting in a moving vehicle can also be considered nomadic. A common characteristic for devices in both cases is carryability, due to the demands of mobility. Mobile device manufacturers are paying considerable attention to the device’s ease-of-use. Nevertheless, using them is becoming increas- ingly diffi cult due to the feature race (the growing number of features), driven by two major trends: 1. user pull, which means that people want more versatile gadgets, and 2. technology push, which implies that the device manufacturers add new technology that is regarded as a user benefi t, or a selling point or differentiation point from the competitors. The majority of mobile device users claim that the devices have become more complex and diffi cult to use, yet the hard evidence is diffi cult to fi nd as a feature is ill-defi ned at best. However, studying the develop- ment of the number of text strings displayable to the user in mobile phones reveals some trends. In 1992, the fi rst-ever GSM phone Nokia 1011 contained 406 display texts, but 10 years later the Nokia 6610 had 3085 texts strings (Lindholm et al. 2003). In essence, the number of strings (not words or characters!) is 7.5 times higher, even though the user interface has not changed dramatically.