Our usual method for fluke dosing, worming etc is to get all the ewes in a wee pen, then after I've dosed each one, Mrs Womble gives it a wee bindi spot on the forehead with a temporary marker crayon:
However, I had to do it on my own the other day, and found I didn't have enough hands to hold everything at once. I solved this problem by drilling a small hole through the knob at the bottom of the crayon, and attaching it to one of these "zingers" (also known as ski pass holders, and available on Ebay for a couple of quid):
It has to be quite a strong spring to take the weight of the crayon, but the one I had did the trick. So all I do now is attach the zinger to the chest pocket of my overalls, and I'm good to go!
OK, I know it's not going to win me the Nobel Prize for invention, but you never know, it might be useful to somebody