Drag background images in 3D view? Is there some way to set the location and scale of background images in the 3D view by dragging or using the mouse/3D cursor to align it, similar to AltMMB in Composite nodes?

Setting the location with the X and Y sliders can be quite difficult, especially since Shift seems to have no effect on those values.
To the best of my knowledge, such functionality is not available out of the box. However, one other way would be to use an Empty with the Display type set to Image. Advantages are that you can move it just as you would any other object and adjust the opacity etc. Another advantage is that it displays in both Orthographic and Perspective view.



If you find it hindering you.. you can always just disable Viewport selection from the Outliner by clicking the arrow.