I have seen this for a few years now, but I just remembered to ask someone.
Why do some people (usually only young black men, AFAIK) wear a hairpick or two stuck neatly into their afro hairstyle?
WAG, while we’re waiting for a more knowledgeable person to come along.
I have decently curly hair, and can actually get it into a (very) loose 'fro when it’s long, but keeping it at it’s maximum poofiness requires a bit of work. With my hair, my fingers usually are enough good enough for fluffing my hair out. However, with an actual Afro, something a little more precise would be needed to get the neat look, something along the lines of a pick.
So a pick is used to get the shape, but the hair won’t just stay put without some supervision, so the pick will need to be brought along. Where’s the best place to put the pick? Well, while putting it into your pock is efficient, you can also just stick it in your hair where it’s within easy reach of a hand that’s putting an errant hair back into place. It also demonstrates how good your 'fro is (I would never be able to keep a pick in my hair without it falling out the first step I’d take).
[white and uptight] I, too, have been perplexed by the comb/pick in the hair as a fashion statement. I can understand the idea that the hair is a practical place to store a comb or pick, but then why not walk around with a toothbrush in one’s mouth, Q-tips in one’s ears, etc.?[/white and uptight]
Hmm, it would certainly make it quite difficult to have a conversation, though. <garble garble garble?>
I haven’t seen this lately myself, but it was common when I was in high school in the early '70s. I don’t know if there’s any “reason” for it other than that it looks jaunty.
LtningBug got it right. Afros (especially giganto ones) have a tendency to get mishapen if you don’t comb them out, like, every hour or so. And the hair makes a good (and fun) storage place for combs, just like the back of the ear makes a good place for pencils and cigarrettes.
OK then, floss? 
Inner city wise, it was also a weapon.
Yeah, getting smacked with one of the ones with metal teeth hurts like a bitch. I do not speak from experience myself, but I’ve seen it happen. I suppose you could get stabbed with one, too.
And a lopsided Afro does not look good at all. Gotta keep it 'froed out.
More of an “attitude”, re:blackness, not utilitarian,IMO.