I don't think this has been posted yet, at least the search function didn't reveal it.

I've taken a FlossCard and wrapped it with a couple feet of 3M duct tape. This rides nicely in my wallet and thus becomes an EDC item. Be sure to make a short "pull flap" on the very end of the tape for easy deployment.

You could do the same thing with an old credit card, but using the FlossCard gives you some EDC floss line as well.