A spice rack for people who actually use their spices. And use them a lot.
Quite a while ago I made this spice rack that takes advantage of wall space above the countertop's backsplash. We bought special jars to contain the spices, printed out labels for them, and arranged them alphabetically. Transferring store-bought spices from the odd and various-sized containers they come in makes it much easier to store. Best of all, since the shelves are only one jar deep, nothing gets lost or hidden.
I absolutely love this system. It transformed the way I cook.
These pictures should give you an idea of how to build it. Nothing too complicated: just some oak shelves and sides and a quarter-inch back panel. The biggest expense of this project is buying the jars, which can be quite expensive.
You should also consider whether you want clear or dark jars. Having clear jars makes it easy to quickly identify a spice and grab it, plus all the colors make a nice display. However, I have read that spices should be stored in opaque containers to keep them fresh longer. From my experience I can tell you that parsley, oregano, basil, and cayenne pepper do tend to fade in color over time, but I haven't noticed any discernible change in flavor.
Update: Here's a SketchUp drawing.