The Hotel Soap Project: Introduction

I used to travel for work much more than I do now. As I come from a long line of tightwads, I used to collect hotel soaps and bring them home. I didn't buy shampoo or conditioner for over a year.
One day my friend Michael discovered my stash of hotel soap. His discovery was the genesis of this project. Over the course of a year, he and his boyfriend Charles collected hotel soap from all over the world: Paris, London, Tokyo, Toronto, Costa Rica. At Christmas they presented me with their loot.
My goal is to evaluate each soap and present the findings here.