I agree with Jorge, it would be interesting to read more about how this method of observing works exactly.

An a different note, does anyone know the rough inclinations of these objects to our line of sight? Or direction of orbit, for that matter?

And the fact that nobody seems to understand it very well (or at least be able to explain it properly) may be an indication that maybe a generic article on the issue might be a good thing to publish by Universe Today.

What do you say, staff?

I think the image released by JPL and Goldstone has been processed and can (to first order) be simulate what an observer floating in space would roughly "see".

See Chris Magri's (one of the 1994CC observers)
page about radar studies of the main-belt asteroid
216 Kleopatra.:

http://academic.umf.maine.edu/~magri/NASC/kleopatra.html

As Emily Lakdawalla explains, "Doppler-delay images plot Doppler shift on the horizontal axis and distance from the telescope on the vertical axis." (from her blog at planetary dot org slash blog; she also displays a noise-reduced version of the anim).
Meaning: radar gives you 2 kinds of information. The time-delay gives object distance; frequency shift ('Doppler shift') gives radial velocity respective to Earth.

Plotting these two as coordinates on a graph produces something that looks like an image, but is not!
I fail at understanding how this 'image' actually relates to the object as we would see it, where is the observer's direction (if any), etc.

Anyone knows of a webpage where this is clearly explained, with graphics?

When imaging near-earth asteroids, Arecibo is used in its active radar mode. So, it does emit a pulse towards the asteroid.

Go to the Arecibo research page at:

http://www.naic.edu/public/research.htm

and look that the entry under "Radar Astronomy"

The common understanding of radar systems implies a radio transmitter which emits radio waves and a receiver which is used to receive those radio waves that get reflected by the objects in front of the transmitter.

But in this case, there is no transmitter, is there? Arecibo works simply as a receiver, detecting the fraction of radio waves originally emitted by the Sun that get reflected by those asteroids. Which is why we see them as crescent. Isn't it so?

If it is so, then why are these images called "radar" images, and not "radio" images, like visible, infrared, ultraviolet images, and so on?