Fortune magazine's just published (online) list of "Business's Hottest Rising Stars" under age 40 features several familiar names in the world of social media.

Coming in at No. 2, trailing only Google co-founders Sergey Brin and Larry Page, is Facebook founder Mark Zuckerberg, whose early business card title was "I'm CEO, bitch." I'm sure Dave Chappelle would have been honored.

(A digressive complaint: Just once, couldn't the creators of these lists separate Brin and Page? It's not like they're Siamese twins, though apparently they still share an office. Plus, in a realistic world, isn't one at least slightly more hot/smart/important/cool than the other? Google workers, feel free to use our anonymous tip line to choose the more valuable co-founder, or post a comment below. Another thing, this is supposed to be a list of "rising" stars. Wouldn't you agree that two guys whose company is now the subject of anti-trust investigations have, you know, already risen?)

At No. 5 are (here we go again with the pairs) Biz Stone and Evan Williams, co-founders of Twitter. I think Biz is more important than Ev. (Actually, I have no idea; I'm just trying to get the ball of controversy rolling.)

Marc Andreessen grabbed the No. 10 slot. Another anachronistic choice, in my view. The Netscape founder has been around forever, it seems. But he did start social networking platform Ning, so he qualifies as a socnet player. In his profile, Andreessen says his "stress reliever" is "hard alcohol." Uh-oh. That can't be good.

No. 18 on the Fortune list is "Pony" Ma Huateng, founder and CEO of Tencent, an instant messaging service based in Shanghai, China. Fortune tells us that "ma" is the Chinese word for "horse." Hmm. Lucky guy.

For the full list, click here.