Yes, Papa Sangre uses real-time binaural 3D sound, www.papasangre.com. I'm not aware of any other real-time binaural solutions. I'd like to know too if there's more. OpenAL and other out of box 3D sound engines are stereo, not binaural.
For basic experiments, put 2 small microphones into your ear canals, hit record, then go for a walk. The result will blow you away :-)
To record your custom HRTF, get an anechoic chamber, put 2 small microphones into your ear canals, then record impulse responses from all directions. Not quite as simple.
Good luck! Post your results here!