All this diversity may seem daunting, but understanding the device landscape is not as difficult as it seems, and there are plenty of resources available to help newcomers and experienced professionals alike keep abreast of device characteristics:
Forum Nokia’s Devices section provides technical specifications for all the Nokia devices, including screen size, colour depth, and browser type. The device-comparison feature enables you to generate custom charts that can compare up to 10 devices.
DeviceAtlas — a dotMobi initiative — contains ‘the world’s most comprehensive database of mobile device information’, including data on more than 3,900 devices. The DeviceAtlas data explorer enables you to create custom charts and tables and compare thousands of devices by manufacturer or property (including colour depth, release date, and screen width).
Forum Nokia offers an online Remote Device Access service that enables you to perform many common mobile-device functions remotely on real devices and includes an excellent real-time representation of your actions on the device’s display. With this service, you can install and test themes and applications, browse mobile Web sites, or simply explore the interface. Data access is also included free of charge. For testing on a wider range of devices, similar commercial services are available at DeviceAnywhere and Adobe Device Central CS4.
Emulators are extremely useful, but nothing beats the insights that can be obtained by testing on a real device. Remember: Your application will be used in many contexts, so don’t forget to take the device for a walk!