Hi Oth,
Unfortunately, Inquisit doesn’t currently support dragging objects like in the web site you linked. This is something we have on our list for a future release, specifically to allow rank ordering type questions.
The only other options for doing this would be to build a web page or flash animation that allows drag/drop, and then host it in the experiment. Note that Inquisit wouldn't know what's happening within the web page or animation, so any data you'd need about those events would have to be recorded by the web page or animation.
-Sean