Per from Stuffmatic.com released an add-on for Blender which provides you with the tools to do a geometry camera matching over an existing still image similar to what SketchUp can do.
It features manual and automatic matching tools as well as focal length estimation and camera orientation. The perspective matching is done through using grease pencil strokes. The following video tutorial explains the process pretty well.
Download & Documentation: http://code.google.com/p/blam/