i, too, have thought about it recently. something to mark a change. i even have a design in mind. and i'd put it on my upper arm - where it could be seen - but not all the time and not too big.
my wife and kids and boss and friends and co-workers would all be totally shocked. they would all think it was completely out of character. maybe that's a good reason to do it! like saying - you don't know as much about me as you think.
They have greatly oppressed me from my youth, but they have not gained the victory over me.
Plowmen have plowed my back and made their furrows long.
But the Lord is righteous; he has cut me free from the cords of the wicked.