I am 'using' something which might qualify as a wallhack. It's called an Audigy 2 with CMSS 3D emulation and a very expensive headset. I can hear exactly where people are by the sound of their footsteps (I can even hear them breathe! ) and predict when they hop around a corner. Also prevents people from sneaking up behind me. Of course, that doesn't work when I'm also listening to music.