Building an iPhone Dolly
An iPhone is currently the most advanced cell phone camera on the market. You can shoot high quality video with this phone that can rival a traditional camcorder. But, because an iPhone isn't a camcorder, you can't use the exact same equipment to control the camera and make it move. There isn't a dolly attachment made specifically for an iPhone, so you need to get a little creative and make your own.
Making a Dolly using Household Products
Anyone can make their own iPhone dolly at home using three things: a skate board, two wooden blocks and rubber-bands. Place the iPhone between the two wooden blocks, and hold them together with the rubber-bands. You want the camera to be held firmly in place with the lens sticking out above the wood, otherwise you won't be able to capture an image.
Place the phone and wood onto a skateboard. The wood will keep the phone from tipping over. Roll the skateboard around, and you now have a low camera dolly. You can tie some rope to the skateboard's wheel axle so that you can pull it.
If you want to raise the height of the dolly, then you should stack wood underneath the phone to raise it's height. Use a ratchet strap to secure the dolly so that it doesn't fall apart in use. You should also place sandbags or some other kind of counterweight on the to the skateboard to avoid it from becoming top heavy.
Using Professional Equipment
Whether you are attaching the camera to a tripod on a doorway dolly or if you're trying to place it on a Fisher 10's head, there are four items that you will need: two cardellinis, one gobo head and a cloth.
Find the best position for secure the cardellini clamp to the tripod or dolly head. Don't worry too much about the angle as long as the pin is sticking out. A gobo head can be rotated 360 degrees, so as long as you provide room for that, you should be fine.
Next, attach the gobo to the cardellini. Then, attach the other cardellini to the gobo. Make sure you position the head so that the knuckle is to the right of the weight it is supporting. This is so the weight of the object tightens the gobo. If the knuckle is on the left then the rig can fall apart because the weight untightened the head.
You can use the second cardellini to hold the iPhone. Make sure that you place the cloth between the metal of the clamp and the phone so that nothing gets damaged.