Apple's iPhone is not due to hit the handset market until the summer of 2007, but its competitors are not just holding fast.

iSuppli reports that Nokia grew its leadership position in the mobile handset market in 2006, shipping more units than its next two closest competitors combined.

Nokia shipped 348 million units in 2006. This compares to combined shipments of 335.3 million units for Nokia's two closest competitors, Motorola and Samsung.

Nokia shipped 106 million units in the fourth quarter of 2006 alone, up from 83.7 million during the same period a year earlier.

However, the biggest wave in the market was created by Sony Ericsson, which in the fourth quarter of 2006 posted the largest quarter-over-quarter growth of all mobile phone makers, with shipments rising 61.5% to 26 million units, up from 16.1 million units during the same period in 2005.

Analysts at ABI Research were not impressed. Even though nearly a billion handsets were shipped worldwide in 2006, handsets failed to "wow consumers."

"Reviewing handset shipments for 2006, you would have to give a B+ for Effort but only C+ for Results," said Jake Saunders of ABI.

Many end users are simply getting bored with the same old lineup of handsets, so ABI expects to see more handsets that break the mold.

In other words, here comes the iPhone, and possibly a new wave of innovation and design in the still-growing global handset market.