I've been collecting up my crisp bags ever since I read a post on My Zero Waste telling us how crisp packets can be reused by women in the Philippines to make handbags.
I finally have an (reused!) envelope full of crisp bags, and I threw in a toothpaste tube for good measure, as they also collect them!
My envelope weighs in at 300g! Saved from landfill, going to charity and I still get to eat crisps! Hurrah!