Here's another sort of stacker:

A shelf w/ two shelves (makes 3 layers of dishes)

a corner shelf w/ two shelves that are spaced a bit farther apart than some versions of this

Another corner version

You can find corner ones w/ only one shelf, sometimes; handy if you have thick stoneware.

another rectangular version

Here's another single shelf.

You could even hang cups from the underside of the shelf above, (if these are spaced too closely for mugs, you can just buy cup hooks at the hardware store) if you're allowed to put holes in the shelf (if you're renting, you could pull the landlord's shelf out and stash it somewhere, then put in your own shelf, have a lumber yard cut the right thickness of plywood to size, and then paint, or use this no-screw, slip-on version of a cup-hook rack)

This long shelf looks nice and low

Here's a ver complicated one this looks like a great idea, but I bet in real life it's a bit of a pain

I keep my china-cabinet teacups in something like this, but it's not so great for mugs

if you have platters, or use placemats this sort of thing can help you use a little sliver of space under the shelf.

these are mail-order sources, but you can usually find these at housewares stores (Bed Bath & Beyond, for example), or sometimes at places like Target. And some of the smaller hardware stores.

Also, I have at times considered getting *different dishes*/

Corelleware is SO much thinner than my mom's Fiestaware, my stoneware, and other sorts of dishes. And I found I needed 3x as much space once I traded in my Corelleware for thicker dishes.

Even my fine china is thinner than my everydayware. And it takes up less space.

I love my Corelle because they are thinner and take up less room in the cabinet and the dishwasher.

I find the single shelf (which creates 2 levels) to be easier to use; almost every place I've tried to put my two-shelf (3 levels) one, the top shelf is completey unusable. Or, it will hold only a single thing, like the butter tray.

The Container Store has some nice versions of this.