A funny thing happened on the way to constructing a jewelry holder for my wife. I need to be able to hold a piece of acrylic at a certain angle.
This thing is a general purpose slotted holder. If you use a pair of these, you can slip something into the slot and you get it held at an angle.
The OpenScad is parametric, so you can change the angle of repose, or the thickness of the base, or the slot gap. Then I thought, 'hay, you can use this as a generic phone holder, or iPad holder, or picture frame holder, or whatever. Anything that need to be held at an angle. Of course, you'll want to increase the length of the base if the thing is too tall or heavy for the repose angle you've chosen. You could modify it to include some extension mechanism.
The really cool aspect of this design, from my perspective, is the OpenScad itself. I was wracking my brain on how to do the fillet, when I finally remembered some basic graphics stuff from when I first learned to program. Just do piece wise triangles following a line.
This is also cool because I've finally figured out how to do Bezier curves and the like. Of course, I'm sure there's already someone who's done this in OpenScad, but it was a fun discovery for me. So, if you're into OpenScad, by all means, get the code for this one, and use the technique wherever you need curves that aren't simply carved out by cyclinders.
The default gap on this thing will accomodate 1/4" plywood (6.5mm).