For all these products, the voice capabilities are being played down in favour of data transmission. There is some commonality in the technology inside the cases as well. The Nokia 9210 and the Ericsson R380 both use the Symbian Epoc32 platform, for example. The Sendo Z100 is the first product based on the Microsoft smartphone platform, and there are similar devices under development. Motorola is a part-owner of Symbian but also has its own platform, and Symbian has licensed its technology to Kenwood, Panasonic, Philips and Psion.

Convergence on two platforms ­ Symbian and Microsoft ­ seems likely, however. Since both these platforms will support some type of Java, the commonality is even more striking. This is good for users, who will not have to relearn everything for every new device. It is also good for manufacturers, which can take advantage of stable software platforms to add their own enhancements.

Crucially, these platforms are usually open, so third parties can add their own applications to the devices. With careful design, a developer could write a mobile application once and it would work on, say, all the Symbian-based products. If that application is written in Java then it shouldn't be too hard to make it run on the others as well.

The three types of mobile data devices most often envisaged are smartphones, tablets and keyboard devices. Symbian aims variants of its platform at these hardware models. Most of the operating code is common, the differences being in the user interfaces.

The RIM BlackBerry product is very popular in the US and Canada ­ the idea of being able to have your office email automatically delivered to your mobile is a very powerful one. In Europe this facility will have to be carried over the General Packet Radio Service (GPRS) standard ­ so it won't take off until GPRS services are available from the mobile operators in a few months' time. Equivalent or enhanced email features will be available on any of the new devices that include GPRS ­ so RIM's advantage won't last long.

Competition will benefit corporates, who will be able to buy products from several manufacturers, knowing that they have at least basic compatibility and that any bespoke software has a good chance of running on a range of devices. It will also be possible to update or enhance software over the air in a secure way, using features of MExE (Mobile Execution Environment).

We should all be pleased about these developments ­ if each mobile manufacturer had gone its own way, the result would have been a much smaller, fragmented market.