The problem with mounting a GoPro to a DJI Phantom or other drone is that the vibration of the propellers creates a terrible jello effect in the footage. This is the main reason that gimbals have become such a popular accessory for drones. But gimbals are expensive.
Two grad students from USC were searching for a cheaper way to reduce the jello effect in their footage from their Phantom-mounted GoPro. After months of failure in testing several aftermarket products, they finally built their own mount with household items for less than $10.
They discovered that they had to dampen the attachment between the GoPro and the Phantom, which is something that none of the attachments on the market allowed. In the end, they used a pair of sponges and some semi-rigid wires to connect a mount that was constructed from a plastic lid.
The results are impressive and resemble the look of an expensive gimbal when viewing the output footage. You can see a full walkthrough, along with sample footage, in the video above.