How to allow visitors to tag our posts themselves ?

Hello,

I couldn’t find a plugin for this, but maybe I missed it, i’m asking just in case…

Would you know if there is a way to allow our visitors to manually add themselves tags to our blog posts ?

I have enough visitors to make it interesting, I’m certain that, if I could allow my visitors to add tags themselves, the results would be new and more accurate than my choices.

Thanks a lot if you have an idea about how to implement this, if you know of a place where that is discussed, if that’s possible of course ??

Best regards,
Sabin