RJ Studios has released Cans2Cones, a headphones-to-speaker emulator that is designed to help a listener make better mixes when monitoring through headphones.
Cans2Cones applies Interaural Time and Amplitude Difference (ITD and ITA) information to a stereo signal that emulates the distance and spacing of loudspeakers in a treated room. A special feature of Cans2Cones is a dynamic de-compression control which helps to overcome the compressed "in your head" sound that can occur due to the close proximity of headphone drivers to the eardrums.
Price: $12.95. Downloadable demo versions are available at the company's web site.