The allure of the PDA in the realm of business isn't hard to fathom. Small, portable and powerful technology has always held great appeal. For style-conscious users looking for the latest and greatest in gadgetry, the PDA is a natural accompaniment to the other essential business item of the 1990s - the mobile phone. The increasing power of these devices has led to growing interest in the corporate arena. Where all that's required is simple data manipulation combined with basic Internet connectivity, the PDA is an attractive option - likely to be a much lighter burden to bear for both the mobile worker and the company bank account.

Because of their size, entering data into a PDA requires either a tiny keyboard or some form of handwriting recognition system. The problem with the former is that they're too small for touch-typing. The problem with the latter is the difficulty in making it work effectively. The solution to the handwriting recognition problem has proven to be the Graffiti handwriting system. This relies on a touch-screen display and a simplified alphabet - which takes about 20 minutes to learn - for data entry. Typically, PDAs with the Graffiti system provide the option to write directly onto the display which translates the input into text, or to open up a dedicated writing space which also provides on-line examples and help.

The end result has been that the PDA market has become segmented between users of the two major form factors; devices that have a keyboard and stylus-based palm size devices that don't. The choice depends on personal preference and the level of functionality required. Following this trend, Microsoft has evolved its CE operating into two separate versions, for each of the form factors.

PDAs still require a "killer app" to make them truly ubiquitous, but the advent of multifunction universal communications tools that combine the capabilities of mobile phones and PDAs looks set to deliver that. The ability to conveniently and inexpensively access the Internet with a single device is the holy grail of mobile computing and one that Palm Computing's launch of their wireless Palm VII in the autumn of 1999 brought this a significant step closer.

One possible outcome is for the market to split in two: those whose desire is basically for a swish mobile phone and who will only acquire a product with modest computing power such as a built-in web browser - users who will be perfectly happy with Symbian-style mobile phones, and those whose requirement is for a portable computer and who want to be in touch while in transit - the market for the wireless PDA class of device.