Best thing I've found is a special clear tape by 3M used to protect the
leading edges of props. In AZ we use 6" wide lengths of this tape to
shield the undersides of our booms from the glass-eating gravel we land
on. It works great for yaw string attachment -- easy to remove but
doesn't remove itself, leaves no residue, very clear. E-mail me your
snail mail address if you'd like a sample (tuno(at)pobox(dot)com).

~ted/2NO