1 Bit of a stretch, isn't it? Chiyo specifically didn't get hit in dodgeball (and when she got pegged in volleyball, it was friendly fire on the back of the head, no?)

2 "Hiccups", right?

3 Gentlemen, gentlemen... you're putting waaaaay too much thought into this.

LOOK AT THE GIRL ON THE LEFT SIDE OF THE PICTURE.

4 The 24 reference had me going for a bit. That damned tick-tock and mulitple frames is going to be with us forever I'm afraid (kinda like bullet-time).

5 I've never even seen 24, and I knew what it was.

Yup, we're screwed for a loooooong time.

6 You're imagining things. That isn't Chiyo-chan.

7 Right, looks nothing like her. What could I have been thinking?

8 The only thing even vaguely similar is that she has short twintails, but they're not drawn the same, and that's hardly rare anyway. (Kinomoto Sakura also has short twintails.)

9 Steven, with all due respect, I believe you to be incorrect.

Oh, you're right, the twintails aren't exactly right. The drawing style isn't exactly right. Here's news: none of the the other cameos in Lucky Star are exact, either, but there's no question who they are.

I believe the situation to be the same in this case.

10 More like, it can't be a cameo because it's YUTAKA. It's a named character. It's Konata's lil' sickly cousin! ;p

11 That could to imagine that?. It does not hope to me that, or it is by chance or by lack of creativity, it got to happen things like these. Although, nevertheless, it is necessary to know clearly that this is one of the many details and particularitities that make interesting not only anime, but to different sorts of programs. That is what I think!

12 More like, it can't be a cameo because it's YUTAKA. It's a named character. It's Konata's lil' sickly cousin! ;p

Yukata has pink hair and green eyes.

13 Last I checked Yutaka's family name was Kobayakawa, not Nakagawa as written on Mystery Girl's shirt. To suggest that KyoAni (peace be upon them) would have gotten that wrong in addition to drawing Yutaka so horribly, horribly off model... well, there are some insults this fanboy won't forgive. *starts sharpening pitchfork*

In all seriousness, it does look a bit like Chiyo-chan would look in the world of Lucky Star, and it's possible that a more obvious cameo would be impossible because of copyright issues. Maybe the storyboard artist was reminded of Azumanga while drawing the scene and this consciously or unconsciously influenced him to include a Chiyo-like girl, but that's about all I can imagine. The scene of Hiyori actually getting beaned isn't in the manga (they only show the before and after), so it isn't outside the realm of possibility.

14 Well, I'll be damned. You're right, that's not here. Why the heck did I think it was? (Gah, Saimoe has fried m' brain...)

15 Take a look at the third picture in this post. Isn't that the same girl?

16 That's what Avatar thought, Steven. That's Yutaka, who has pink hair and green eyes. My Chiyo-clone has brown/red hair and not-green eyes.