I have a new flatmate and needed a new spot for her toothbrush. My previous design was good for a single toothbrush, but this one can hold up to three. I think the design could be more compact if all the brushes would go in the same direction. You can fix this accessory on any surface with small circles of thick double-sided tape.
just added a 4 toothbrushes version
If someone asks me, I could design a version with 5 or more toothbrushes.