Fallout: New Vegas
File Location: My Documents\My Games\FalloutNV
adding the following lines to FalloutPrefs.ini worked for me. I set the file to Read-Only afterward to prevent it from being overwritten.
YOU MUST SET THE FILE AS READ-ONLY AFTER THE EDIT!!!!
if you don't steam will erase your changes once you load the game.
I'm kinda nervous about steam though. Since it kept rewriting the file, i have a bad feeling it's gonna screw up some modding potential.
Go to the Official Fallout Forum and vote;-)
like that will actually do anything.
Bethesda never added a toggle to F3, and obsidian is never going to add a toggle to FNV.
So you just do this and your good.