TOCollectoREX is utility replacing and supplementing standard Resource Collector.
It allows gather all scene resources together, put them in specified place, find where all missing files are used (exactly in which objects). It can find which files in specified place are no longer used by scene. It also allows convert bitmaps to jpg, etc.
Utility supports XRefs of all types and processes all scenes linked to current.
Unlike all other such scripts, it really finds all resources (images, HDR-images, Vray meshes, IES-files, shaders), not only some bitmaps (Relink Bitmaps, Resource Collector). Below there is full description.