Going a bit more deeply on how KDE SC 4.4 will support multitouch, here are 3 longer videos:
The first one shows marble. Is now possible (with the usual disclaimer on devices and systems that support it, hoping it will become a more pervasive feature) to zoom the earth with a two fingers gesture, making a retty natural interacion
The second one shows Plasma: it’s possible to move, resize and rotate the widgets with two fingers, making them a bit more “real objects”. Another place of Plasma that supports multitouch is the “Blackboard” widget (painting with two fingers simultaneously ftv) and all the animated scroll widgets, such as the one used in the microblogging plasmoid and in the netbook and the webkit based widget.
The last one shows in detail the Webbrowser widget, in particular two fingers scrolling (note that is still possible to select text with a single finger, while scrolling with two) and pinch zoom with two fingers again, all correctly maped to any transformation the widget can have.