Just found an article on recycling old tights,
there are ideas for the home and garden and I am told they accept old tights, with or without holes as long as they are clean, and they are used to secure dressings on women in developing countries who have suffered in injury in childbirth... the charity part seems to be broken at the mo but it could just be my internet connection
Click on the links on the website for more info
http://www.tightsplease.co.uk/eco-friendly/