A study conducted by User Centric has found that it takes QWERTY keyboard users almost twice as long to create the same message on the iPhone.

"For QWERTY users, texting was fast and accurate", said User Centric's Jen Allen.

"But when they switched to the iPhone, they were frustrated with the touch-sensitive keyboard."

A study of only 20 participants, half had previously owned a phone with a QWERTY keypad, while the other half were used to a numeric keyboard.

Steve Jobs talked about the iPhone's touch-only keypad quite extensively before the phone launched:

"Like all small keyboards, it takes 3 or 4 days to get used to. iPhone users will quickly learn to trust its intelligence to correct their mistakes automatically."

"So far, everyone who has used it loves it and reports that they are typing as fast or faster than they did on their Treo or BlackBerry or other smartphone."

"We think the iPhone's keyboard is one of its greatest assets and competitive advantages."

It seems a fair point that users will have to get used to the interface before they can match their previous standard-keypad speeds, well, unless they chose to jump the gun and just get their thumbs whittled instead...