The pilot conducted the pre-take-off checks, including the engine runup, while taxiing for take-off. This resulted in a higher than normal taxy speed. Anticipating a 180 degree turn to align the aircraft for take-off, the pilot moved the aircraft to the right of the strip and looked back over his left shoulder. The right wing struck a four metre high tree which was located 10.5 metres to the right of the strip centreline. The aircraft pitched forward, lurched to the left and the left wing struck the ground before the aircraft settled back onto its gear. The pilot had suffered a delayed DEPARTURE earlier in the day due to the requirements of his business. He had not operated into the strip previously and did not notice the tree during an aerial inspection prior to landing.