On August 2, 1997, at 1535 central daylight time, a Piper PA-24-250, N720MB, received substantial damage while taxiing for takeoff at the Fond Du Lac Airport, Fond Du Lac, Wisconsin, when control was lost and it struck five other parked airplanes. The private pilot reported no injuries; however his passenger sustained minor injuries. The pilot said that control was lost when he applied power to get over the lip of the taxiway. The 14 CFR Part 91 personal flight was operating in visual meteorological conditions. No flight plan was on file. The airplane was preparing for departure at the time of the accident. The pilot said that he had to use about three-quarter throttle to get the airplane to move up the incline to the taxiway and when the nosewheel bounced onto the taxiway it was turned to the left and he lost control of the airplane. An examination of the airplane after the accident failed to reveal any preexisting anomalies. The throttle in the accident airplane was a vernier control type and required pushing a button or rotating to change the throttle setting. The throttle was found in the full forward position. An examination of the throttle found that it was connected to the carburetor and functioned. The mixture was in the full rich position. A check of the mixture control found that it was connected to the carburetor and functioned. The magneto switch was on both. A check of the switch found that it functioned at the leads on the magnetos. The airplane had a hand brake which operated brakes on the main landing gear. The brakes were examined and functioned. The pilot had a total time in this type of airplane of 16 hours. Of this time 6 hours were solo. The flight from his home airport to Fond Du Lac was about 3 hours. This was the first airplane he had flown which did not have toe brakes or friction (other than vernier) throttles.