If the vendors at last week's CeBit show are to be believed, the mobile phone is about to get a lot smarter. But as Tony Hallett argues, packing all that functionality into just one small box might not be the best way forwardThis year's CeBit event in Hannover has been marked by a flurry of announcements from key mobile telephony and IT companies. A lot of press coverage has focused on which suppliers will come out on top - with the Microsoft versus Symbian prize fight arguably heading the bill. But looking at the ways the devices themselves will be used is actually more interesting. Traditionally, the spotlight has been on the promise of the all-in-one 'smartphone' - a wireless phone-cum-computer running a compact operating system from (probably) either Microsoft or Symbian, the joint venture formed last year by Ericsson, Motorola, Nokia and Psion. The argument is that once third-generation GSM, or UMTS (Universal Mobile Telecommunications System), becomes a reality, users will be able to do almost anything, from anywhere, at speeds of at least 2Mbps. A forerunner to these devices is the Nokia Communicator, which although slower and less powerful than future smartphones, captures the imagination in the same way. But this is the wrong way to think about coming developments. Theresa Torris, director of the European new media analysis division of Forrester Research, says: "It's like having the option of buying an all-in-one TV and VCR. If the video goes wrong - and it is generally more likely to do so than the TV - then you have to fix the whole device. Vendors shouldn't try to squeeze too many devices into one box." Indeed, the latest version of the Nokia Communicator stands in direct contrast to one of Ericsson's big announcements last week. The Swedish manufacturer unveiled the MC 218, its first offering based on the Epoc32 operating system which is now being nurtured at Symbian. But this isn't an all-in-one device: instead, it works with an Ericsson mobile phone handset. The MC 218, which will be made by Psion, allows email, fax, SMS text messaging and Internet functionality to be added to a GSM phone. Another reason to imagine a world of multiple mobile devices is the promise of the Bluetooth alliance. A consortium of several dozen leading high-tech companies - headed by Ericsson, IBM, Intel, Nokia and Toshiba - is touting Bluetooth technology as a way of allowing high-speed voice and data transmission over short-range radio waves. The consortium claims Bluetooth will mean fewer connection cables and allow automatic synchronisation between devices, without depending on infrared. Imagine a business user with a small, UMTS mobile phone that connects via Bluetooth to a small PDA, which she keeps in her briefcase. She also wears a watch that alerts her when she receives an email. The combinations are almost limitless. And Forrester's Torris believes the devices need not even communicate locally, using Bluetooth. "You can see applications being stored and speaking to one another at the server level, because you could end up doing very different things with devices, especially if you take into account digital TV and PCs," she says. CeBit saw major mobile network operators put their faith in the smartphone, not least NTT DoCoMo, which until Vodafone and AirTouch merge fully, remains the world's largest operator. So with such across-the-board backing from the industry, smartphones seem set to make a big impact on our lives. But the form they take - and the way we use them - won't be so set in stone.