Mobile terminals have evolved from basic portable telephones to complex and diverse devices that encompass dozens of other features, ranging from tri-dimensional games to office suites with data transmission capabilities. Variability is value: mobile terminal manufacturers must succeed in fulfilling the requirements of hundreds of mobile telecom operators worldwide, and at the same time increase the value of their brand by adopting a common user interface style while offering the features that the target end-user category desires. This makes for practically infinite variability and creates a business problem. The complexity of the variability problem increases due to issues such as the ability to 'plug and play' and 'feature descension' (the down-scaling of high-end features and their introduction into lower-end models). The main lesson we have learned from our experience in this field is that the application of relatively simple architectural patterns usually eases up management of the complexity at the architectural level. However, tackling the variability problem at the technical level is ineffective unless the organization is able to ensure the application of the solutions. We analyze the main challenges that lie behind the variability problem in mobile terminals, at both technical and organizational level, and illustrate some of the solutions we have implemented together with our product developers and system architects. Our experience calls for more applied research in the area of variability management, as well as for a number of enhancements to academic curricula. Copyright © 2005 John Wiley & Sons, Ltd.