Mobile devices are hot, hot, hot, and anyone who has bought a new one gets a rush out of showing off their newest toy to their friends, for they are hip, they are happening, they are the epitome of hi-tech coolness. Followers of the PalmPilot cult are writhing in anticipation as rumours circulate about a new generation of Palm OS devices codenamed Razor. As 3Com has been uncommunicative on the subject, we can only conclude that it will be sleek, will support a colour screen and will be half as thin as current models. Following close behind is Microsoft and a new and improved version of Windows CE, the operating system for PDAs. Version 2.1 may be ready, but gadget gurus are predicting that handheld devices will not be dreaming in colour until next year. But Microsoft is not going to stop there. A new class of CE PDAs codenamed Jupiter will be launched any day now. And you better watch out because computing titan IBM is hurling itself on to that market. Not to be left out, two companies better known for mobile phones, Ericsson and Nokia, have joined Psion to further the development of the Psion OS for licensing to other manufacturers. Codenames are big these days, and this joint venture has been christened Symbian. Symbian will be developing the OS for use in future cell phones and voice-enabled PDAs. Ericcson, Nokia, Motorola, IBM, Toshiba, Intel and Symbian are co-operating on another project, codenamed Bluetooth. It is a wireless technology that should replace cables required to link PDAs, cell phones and notebook computers, and should be superior to infra-red devices because you do not have to point the machines directly at each other.