I'v been following HomeMadeModern for some time since they have some great DIY furniture projects with wood and concrete elements. Their design is very modern, minimalistic and easy to build.
In this project a better dish for dog food is built. It is curved and angled on one side so the dog can get all the food.
They use 3d printed full size prototype to create a mold and then poor the concrete mixture in.
The results look very good. You could use this technique to create any object in concrete, only limitiation would be the size of your printer.
If I catch some time in the future I'll try to build speaker housing made from concrete similar to P.A.C.O. open source project.
Great project! I like the idea of concrete furniture pieces, I don't have any experience with them, but even the concept seams better then those horrible IKEA pieces. And you can make them as unique as your own creativity.