During the takeoff roll, the pilot noted that the airplane was rolling longer than expected and suspicioned that he might have been on the brakes a little. After a short local flight he returned to land at the private airstrip. Right after touchdown, he applied the brakes firmly and then released them as the airplane started down a dip in the runway. The pilot noticed that the brakes did not release and were dragging. As the airplane continued to slow, the tail of the airplane started to rise until the airplane nosed over, and came to rest inverted substantially damaging the right wing and lift strut. After exiting the airplane, the pilot attempted to turn the airplane’s wheels and found that they would not turn by hand. The pilot cycled the parking brake valve which fully released the brakes. The pilot reported that there were no mechanical failures or malfunctions with the airframe or engine that would have precluded normal operation.