I threw this up on Metafilter too, but why not here? Lazyweb, a question:

On a whim, I've added zipper pulls to a bunch of my clothes and coats. It's such a small, inexpensive thing but it's an improvement I notice dozens of times a day, especially wearing winter gloves.

So I'm thinking about aggregating marginal gains now, and wondering what other options like this I have. What is the _smallest_ thing - in terms of size, cost, effort, whatever - that has made your life better in some way?