I might be a bit obsessive about finding the smallest, lightest things to travel with. 😀
I found this company, Midwest Bottles, a few years ago, and have been really happy with the items I bought there.
The website is a bit difficult, their market isn't really small orders (but they don't have a minimum), they don't take returns, and their shipping seems high (but the items themselves are really cheap).
That said, I use these 2 items a lot, and think they are just about perfect:
1/2oz. Liquid Dispenser