Prince Siddhartha, the future Buddha, made a radical gesture back in the 6th century B.C. by shaving his head (hair being at the time a symbol of royalty and the excesses associated with it). Afterwards, the prince called himself only by his last name--Gautama--and wandered outside the palace walls, a vagabond in search of wisdom from spiritual teachers of the day.
To this day, the initiations of Buddhist monks and nuns often include the practice of head shaving.
While most people spend lots of time and money on their hair, Buddhist monks and nuns shave their heads. They are no longer concerned with outward beauty, but with developing their spiritual lives. The shaven head is a reminder that the monks and nuns have renounced the home life and are a part of the Sangha.(The Basic Teaching of Buddha)
Oddly, though the Buddha went to all that trouble to get rid of his hair, according to some, it's still with us. Apparently, in China, carefully preserved locks of the Buddha's hair were uncovered in Hangzhou in the ruins of a pagoda. And as recently as 2007, Bangladesh donated a few strands of Buddha's hair to Sri Lanka. So for all the detachment from this world symbolized by shaving off one's hair, a cultish, reliquary event has grown around the Buddha's hair that gives one pause.
I think Buddha did not intend for his hair to be so obsessively preserved--quite the opposite. I especially like the Enlightenment Ward's musings on the subject. In a nutshell, hair is a problem only if it matters too much.