Previously in my Role-playing games, we always used Star Wars Miniatures maps no matter what the setting. Unless it was one of those time where I set up terrain and we used inches instead of squares. It was fun, but we had to use the same maps for many different things, and the maps were always exactly the same.
Now, using a set of wet-erase markers, I can just sketch a quick map, add in any important details (Cover, computers, equipment, all that fun stuff) with another color or two, and voila! A different map.
I will point out for other potential buyers the mat came with a "Care & Feeding" sheet (That's right, care and FEEDING. Weird, huh?) that says NOT TO USE DRY ERASE.
DRY ERASE can stain it. Use only water-soluble pens, it says.