Michael Harris's concept gadget, "The Nail Assist," looks like a good idea: a proxy for the nail head that's larger and wider, giving you room to put your fingers somewhere unlikely to be smashed. Of course, it all depends on whether the device can stand up to being repeatedly smashed with a hammer.
You insert the nail inside the guide tube. Position the tube where you want the nail to be. The large top makes it much easier to manage a hammer slamming down on it. It also protects your precious and very useful fingers. Once the nail is pushed in, simply repeat the process. Your nail will always go in straight and square into its intended target. Brilliant I say.