I use them for spices (at home for loose spices purchased, and also smaller amounts for travel spice kits).
Also travel kits for bathroom/health items. You can stuff a lot of cotton balls in them, and the longer ones are great for q-tips. Good for traveling with vitamins and OTC meds without having to bring the whole big jar along.
I also use them for travel sizes of lotion and many other toiletries like sunscreen, aloe vera, toothpaste, Vaseline. Those lids are SOLID!
Good for office supplies for traveling as well - paper clips, staples, pins and tacks, pencil leads, a sewing kit.
I also try to get my meds in 90 day supplies instead of monthly, which saves on a lot of bottle waste.
Anything left over I do this - I clean them and remove the labels, place them in a quart ziplock bag and then, with a sharpie, I write on the bag - For Crafts. Then i drop them off at Goodwill. I do the same with wine corks, BTW. Crafty people can find all kinds of uses for such things.