Nothing. Okay, not nothing: tape your broken pinky toe to the nearest other toe, ice and elevate and take some ibuprofen or Tylenol. If you go to the doctor and they confirm it's a broken toe (by X-Ray), the doctor will tell you the same thing.
I broke one of my pinky toes when I was a teenager by banging it against a chair as I was whizzing around my bedroom. I broke the other one last Tuesday when I was whizzing around my kitchen, trying to make yogurt. In order to make yogurt, you have to monitor the heat of the milk very closely so as to keep the probiotics healthy and happy. So I was whizzing. Also, being pregnant, I am extra clumsy these days, forgetting I have about 22 extra pounds on me and that my center of gravity is a bit off. So now I have an impressive dark purple streak running down the center of my right pinky toe. I figure it's just another way my body is telling me to slow down and quit the whizzing already.