Leslie Cook

The hashtag is 10! Yes, the symbol that started out as the lowly "number sign" or "pound" on the telephone keypad and later morphed into something entirely different is 10 years old today. And it has accomplished quite a lot. In fact, it's hard to imagine modern communication without it.

And you might think it was all by design. That the folks running Twitter needed a catchy little tool to help their new platform catch fire, and the hashtag is what they came up with.

But that's not the way it happened.