Here's my small collection of Altoid Tins
I have a coworker who eats these things all the time. He doesn't use the empty tins, so he asked me if I wanted them for anything, I'm such a pack rat I couldn't resist the offer. A quick search on Google will show you a crazy variety of projects people have used Altoid tins for.
What have I done with mine? Absolutely nothing, besides taking a picture of them. Just something more to add to the list of things that I haven't gotten around to doing yet.