This scene from A Study in Pink is shot handheld on a dolly.
Steve Lawes is holding the camera himself on his shoulder, but is sat on a dolly. The grip moves him along on the track while he’s shooting. It gives the scene the dynamism of a handheld shot, but also allows the camera to track low behind the reporters. (You can’t shoot handheld that low b/c a camera has to rest on your shoulder and you’d be doing a crab walk to get that low.)
Doesn’t it make it seem that you’re watching Lestrade and Donovan from Sherlock’s practically omniscient point of view? I like it.