Generally, about once a month the wife cuts it.

Right now, I am debating letting it grow for a year, cutting it all off and donating it to the Cancer Society. My brother did this, and it just seemed like a cool thing to do, if I can stand to let it grow that long. I figure why not, I have good hair, and lots of it, so donate it to some cancer victim. Will take a little more care, but in the big picture, what is a little shampoo.