Having tried it, Gianluca's suggestion of using a polygon works satisfactorily when plotting a single dataset. I had to combine the Polygon graphics primitive with the Line graphics primitive to join up the points with a line (drawing a line around the polygon doesn't produce the desired effect because it closes the polygon). However, like my rotation workaround, it's far from ideal. And it becomes increasingly messy to implement with the various options available in the ListPlot function when plotting multiple datasets. Which is a common requirement for me. I think an option to fill in the horizontal direction would be a good addition.

There also appears to be a bug in the ListPlot function. This occurs when the Epilog or Prolog options are used in conjunction with the ScalingFunctions option set to "Reverse" (another common requirement). In this case I've had to negate the y-values when they're used in the Prolog/Epilog section. My workaround this issue has been to introducing a scaling factor (either plus or minus 1). A simple example that illustrates the issue is attached. Would be good to know whether it's a real bug or a mistake on my part.

All the best,

Ian

Attachments:

One way is to use graphic primitives:

Graphics[Polygon[
  Join[{{0, 0}}, 
   Table[{Cos[t], t}, {t, 0, 2 Pi, Pi/10}], {{0, 2 Pi}}]], 
 Axes -> True]