The pilot stated that just after takeoff, the airplane entered "uncoordinated flight to the left." He applied right rudder to correct, but felt that the rudder was ineffective. After clearing trees at the end of the runway, the pilot elected to conduct a precautionary landing in a field. He stated that the airplane's rate of descent was "high," and that the nose landing gear collapsed upon touchdown. The airplane subsequently nosed over and came to rest inverted. Postaccident examination revealed substantial damage to the engine firewall, both wings, and the vertical stablilizer. Examination of the rudder controls revealed no anomalies. According to the pilot, his passenger was "apprehensive" about the flight, and inadvertently applied pressure to the left rudder pedal with his foot throughout the takeoff and accident sequence.