My personal favorite is put an ice cube in each indentation, and let cubes slowly melt. Wait 12 hours, blot up wet spots, then use the edge of a spoon to lift carpet fibers back up. Or steam away dents: Place a clean, damp cloth over them and hold an iron, on medium heat, several inches above the cloth for about 30 to 60 seconds. Don't let the iron touch the carpet -- it could burn! Brush up fibers with a coin.
More information at www.chemdryfivestar.co.uk