Maybe stupid but you could wear it on your camerastrap?If you wear it on your backpack and you store your backback at an attraction there is a slim chance it can be stolen. We have seen people pickpocketing right inside DLP. So there is always a possibility it will happen.Sadly also inside the "happiest" place on earth theft happends But I think myself that the chance is very small
it is possible to buy hip lanyards on ebay or from America, they have a clip which attaches to a waistband or something similar and is extendable