Q is for Qwerty. This is the layout of almost every computer (and other typing) keyboard in the West - a fine example of the way that market inertia can prevent changes arising that might bring small but measurable benefits.

Legend has it that the original layout was intended to slow typists down. This is not true: it was to allow people to type as quickly as possible, within the constraints that existed when the machine was invented. In early typewriters, fast typing jammed typebars that were close to each other, so the layout tries to separate common pairings of letters. The jamming problem was eventually solved with springs, but the odd layout survived.

But a rival keyboard design, developed in the US in the 1930s by August Dvorak and his brother-in-law, places the most commonly used letters in the home (middle) row. On average, 70 per cent of Dvorak keystrokes land in the home row compared with only 32 per cent for Qwerty, reducing overall finger travel and time between strokes. (The layout reads, from top to bottom, ',.pyfgcrl aoeuidhtns ;qjkxbmwvz).

A US Navy study of "novice" typists during the Second World War purportedly found a 40 per cent speed advantage over Qwerty layout. But the study was carried out by the Navy's chief expert in time-motion studies - Lieutenant- Commander August Dvorak. And the data were clearly manipulated to exaggerate the performance of Dvorak's keyboard.

In contrast, an IBM study in the 1950s concluded that Dvorak's small speed advantages did not outweigh the cost of converting. Later studies - and the free market - have agreed.

Ironically, these days converting to a Dvorak layout has almost no capital cost. The key layout of a computer is determined by the software, so you can easily change the letter that appears when you press any key. Free software for doing this is widely available on the Internet. The mental conversion takes about a month.

And there is one big advantage: nobody will be able to hack into your system from your keyboard.