The ARRI ALEXA is a very cool camera. Out of our budget range at the moment but we can still dream. And that dream becomes very real if you want to get an idea how it operates as ARRI have come out with the ALEXA Camera Simulator (ACS-1).
This is an interactive training tool to help you familiarize yourself with the menu navigation of the new ARRI ALEXA Digital Camera. The ACS-1 Main User Interface shows an identical simulation of the current ALEXA with software version 2.0.
If you go to their website here, you can have a virtual demo by using mouse or fingers (if you've got a touchscreen).
The Simulator is also available on iPad as a stand alone application capable of working offline. Here's a link to the camera's user manual.