I read the manuals that come with my radios. I pretty familiar with the equipment before I pack up and go, but in the field you'll sometimes have a question that a quick glance at a manual would answer immediately. That's where these Mini-Manuals shine. Each Mini-Manual is light, waterproof, with an easy to read print that is color-coded in such a way as to bring your eyes quickly to the relevant piece of information you're looking for (or, at least that's how it works for me). The plastic lamination ensures it will survive all but the harshest treatment.
I have one of these manuals for nearly all my radios: IC-706IImg (in the car), FT-897D, Elecraft K2, and quick reference cards for the Yaesu VX-5R, Kenwood TH-D7A(G), and Elecraft KX1. I also own their "field reference" manual (two, actually), and a couple of other of their offerings I've not mentioned. At this point, these little waterproof wonders are a standard part of any kit that travels as they weigh nearly nothing, have all the information I need that any manual would likely contain, and it means I can leave the original manual at home where it can be safe and dry. Sure, they cost a couple of bucks, but it makes no sense to me to spend lots of time, money, and effort to get to some far away place only to be stymied by a forgotten setting or quirk in the radio. These manuals help ensure that mishap doesn't happen.
As I said, at this point, I order the manual even before I order the radio. Highly recommended.