Geraniums are often called cranesbills. These long narrow fruit are the reason. They are particularly interesting as they dry and drop their seeds. The outer parts peel forward, leaving a central spike surroundred by the curled coverings at the outer tip. And as you can see with this Carolina cranesbill, they can be eye catching at earlier stages. These seed pods are about an inch long.
An aside: it's now 10:13, and I just edited the early morning entry above to explain that the seed covers curl forward. That's what makes them different. Maybe I should get up later?