Help a charity, get a ScienceBlogs blogger to shave his head.

Over at Starts with a Bang, Ethan Siegel lays it on the line:

I have a challenge for everyone who reads this.

Donate at least ten dollars (or ten euros, or ten pounds, or whatever's the closest equivalent in your currency) or volunteer at least four hours at whatever charitable organization you choose.

When you do it, leave a comment at the bottom of this post, telling us:

1. what you donated/volunteered to do,
2. what organization you donated to/volunteered for, and
3. why you chose that organization.

When I get 100 unique comments from people who have done this, I will shave my head.

If you take a gander at the pictures Ethan has posted, you'll see that a fully-shorn head will be a big change for him.

Let's help his scalp see daylight. I've just given some money through DonorsChoose to help a classroom in a high poverty school in Northern California to buy some microscopes. But the comment count on Ethan's post hasn't hit 20 yet -- far short of what he's asking before the head gets shaved.

Don't forget, you don't have to donate money -- if you donate four hours of your time to a charitable organization, that will count, too.