There are different modes available. Most of the time you use your screen like a touchpad of a notebook.

Obviously, we don't have mouse buttons, so button clicks are also just finger taps. Tapping with ONE finger is equal to a left mousebutton click.

A right mousebutton click is done via holding down one finger on the screen and tapping with a SECOND finger. This "alternative touch mode" is also used for other functions.

To enable or disable the touchpad mode put one finger on the screen and swipe with another finger from left to right.

If touchpad mode is disabled, the crosshair cursor will "jump" to the position you tapped with your finger. Additionally a left mouseclick is done.

To enable or disable the drag'n'drop mode put one finger on the screen and swipe with another finger from bottom to top.

This mode is needed for games like Full Throttle which need one mouse button held down for the actions selector or similar.

Swipe with one finger from bottom to top, from top to bottom, from right to left or from left to right.

Put one finger on the screen and double-tap with another finger on the screen

Put one finger on the screen and swipe with another finger from top to bottom

The keyboard is shown if the iPhone/iPod touch is oriented vertically, i.e. in portrait mode. It is hidden if the iPhone/iPod touch is oriented horizontally, i.e. in landscape mode

Those keys are mapped to the row of symbols right below the numeric keys (1234567890) of the keyboard.