Question Tagging

I see that there was a request for categories setup before, and it was pushed to 5.x, my question is simmilar and id like to see if theres a way to impliment it now, i will be having a large question bank, and several quizzes that pull from the same question bank, i would like the ability to add tags to the questions and possibly have them searchable from a quiz "Manage Questions"

i wonder if it would be easier to try one of the following options:

* put a custom tagging system into this setup, it could eliminate or at least postpone the need for categories
or
* use an existing tagging system thats available elsewhere and just code the "Manage Questions" search area to look in that field as well somehow

I may be off on the specifics or may be missing something thats available now in one form or another.