According to the research company, IDC claims some 5.5 million handhelds were shipped last year, down 28.5 per cent, and that the downturn is becoming more acute as the last quarter of the year showed a 35.9 per cent drop year on year to 1.5 million units.

There were a couple of success stories among the numbers. Palm retained its crown, with a 36.3 per cent market share for 2006. However, that still amounted to a decrease in volumes of 28.3 per cent year on year.

In the full year figures, Sharp made an unprecedented entry into the top five, with a 275.7 per cent annual shipment growth, and in fourth spot, Mio posted a 29.2 per cent annual growth to take just over 8 per cent of the market.

Although Mio hadn't done enough to pip Dell in third place over the year, the quarter did see Mio edge ahead to take nearly 9 per cent of the market.

Mio's strength has been in markets in Asia and Europe - markets where Acer, which just managed to get into the fifth spot for the last quarter - is also competitive.