The Eight-Disc Transfer

A tower of eight discs rests on the left peg. Every disc has a different diameter, and the discs are arranged from largest at the bottom to smallest at the top. Two other pegs stand empty. Your task is to rebuild the entire tower on the right peg. You may move only one disc at a time, taking the top disc from one peg and placing it on another. At no point may a larger disc rest on a smaller one. What is the fewest number of moves needed?