While most people use the standard QWERTY keyboard layout, one of the most used alternative layouts is Dvorak. Some people believe Dvorak is more efficient for various western languages since it places vowels and the most commonly used letters right under your fingertips. iPad owners who are used to this layout may find it disappointing that the iPad does not yet have support for Dvorak.
While it is not in the current version of the operating system used on the iPad, Dvorak keyboard layouts are popular enough for Apple to implement them sooner rather than later. As noted in this TUAW article, the latest software developer kit for the iPad shows Dvorak as a keyboard layout option, indicating it is coming soon. We might also expect other popular layouts to make their way to the iPhone OS, hopefully in the iPhone OS 4.0 update or very soon thereafter.