Using an intergrated compositor (Blender, Softimage, Houdini) it is possible to create an interactive studio environment to drive the IBL in a 3d scene. By wiring a couple vector paint nodes together in Softimage I can create an interactive environment map; then I use the map as the source image for the final-gathering or environment sampling.  HDR Light Studio is a standalone product that does just that. Read about the setup in Softimage here.

This environment sampling setup was used in two, full-scale production, Tony Hawk video game projects. 

A few terrain displacement tests. Used 3delight and mental ray to achive these results. The mental ray renders were enhanced with normal maps. Bump mapping wasn't necessary for rendering with 3delight; displacement results hold high detail with low render times.

If you use CrazyBump or Xnormal to generate normal maps, I find this shader very helpful for the tuning process. It removes the need to 'tweak' parameters in a separate app. The author's (Felix Reichert) site is here. 

Testing camera projecting into a 3d scene. The concept is to unload heavy math caluclations from the renderer by reprojecting the final composite onto the 3d geometry, and then quickly rendering depth of field and motion blur. Arnold makes such work-arounds obsolete, but in mental ray and other raytracers, these cheats go a long way.