We recently got these drinking glasses, and I decided I wanted to make it harder to spill 21 ounce of fluid all over myself and my desk (yes, it's happened before). Also, it saves desk space which is always a plus.

The included STL is a tad smaller than I had wanted, so the glass doesn't slide "through" the holder as far as I wanted, but it's still stable. If I print another one, I'd probably make it about 2-4% bigger.