We received one of these Ceramic Ginger Graters ($5.95, Amazon) from a friend as a gift a couple years ago, and at the time we were a little skeptical. It looked like one of the one-use tools we avoid.
Now, however, we love it. Whenever we need just a little something grated we reach for this first; in fact, it never goes in a drawer but hangs on a little hook on the backsplash.
The grater has little ceramic nubs on it, instead of holes. When you grate ginger it quickly grabs the pulp and the juice, leaving the tough fibers behind on its washboard front. It is fantastic for grating all sorts of other things too; it grates hard cheese into snow flurries of fine flakes, and it's perfect for fresh nutmeg and cinnamon. When we want just a little to finish a dish or top our oatmeal we always reach for this.
Straw Mat from The ...

How does it compare to a microplane?
I've been thinking about getting one, but had the same reservations you did. I have a nutmeg grater that needs replacing, so I'm going to give this a try.
We had one of these growing up, but I never knew what it was for until a few years ago when I saw one in a catalog. We had always used it as a spoon rest on the stove. Durr!!! Now I'm wishing we still had it.
It's pretty different from a microplane, mary. It's not sharp, for one - the little nubs are rather rough. Sometimes I grate nutmeg on a microplane but I find that a lot gets caught in the sharp edges. The ceramic grater releases things more easily and you can swipe your finger over it to get things out. It's easier to clean, too.
I use the microplane for cheese more often than I use this. I find this is really good for individual servings or small quantities - when I don't want to dirty my entire grater.
We have one of these too, which mainly serves a decorative purpose in our kitchen. I may have to try it for ginger, though. Since ginger's fibers are so tough [but directional, like the grain of wood], they often resist mincing with a knife. So when I want minced ginger, I'll peel a chunk, then slice it into coins maybe an eighth-inch to a quarter-inch thick. Then I'll smash these with the side of a knife. Works like a charm.
I love this kind of grater, but only use it for ginger. I also have a fine microplane, for snowy hard cheese, nutmeg, etc.
It pulps instead of shreds.
I love the juice that gathers in the well, which is fantastic when you want to finish a dish or drink with a snap of raw ginger flavor.
And it's cute, so I hang it on the wall . . .
hmmm, just took a 2nd look at your picture - mine has a lip, forming a little well, instead of a straight slide at the bottom.
I used one of these ceramic graters for a while, and I didn't find it very functional. Most of my ginger or garlic pulp got stuck in the grating surface instead of going into my cooking.
I love mine, have used them since childhood. Plus they're lovely to look at.
Tessa, after I'm done shredding the ginger on the nubs I use the bit that's left in my hand to sweep everything to one side (rub crossways) and then I either squeeze the pulp to send the juice streaming into something yummy or plop all of it into my cooking.