TUAW (The Unofficial Apple Weblog) points out this New Media device which can help you get smooth “dolly” shots using your iPhone or other small camera. (See Hello, Dolly! Meet iStabilizer’s new iPhone moviemaking accessory)
The Dolly is a combination of smooth running skate wheels, a positional arm and standard tripod mounts that can connect to your iPhone or other camera. rolling the Dolly gives you smooth “dolly” shots around your scene or actors at a fraction of the cost of a true dolly rig used by mainstream productions.
You can see several demonstration videos on YouTube to give you a feel of the type of shots you can achieve with the Dolly.