After I got all of the vibration issues under control with my quadcopter, I made some longer landing gear and put my Gopro on the bottom of the quadcopter. On the first flight I have vibration issues, because I took off the support for the arms so they flexed and amplified vibrations. After I put them back on, the quadcopter flew well. Here are the videos I have made so far and some pictures of how the camera is mounted.
First successful video:
Flying the quadcopter up and down the road while walking along behind it: