Lake's Dolby Headphone PLS is a available as a plug-in for MusicMatch and RealJukebox Plus. Lake originally developed the technology, and then licensed it to Dolby for distribution worldwide. More info can be found at
www.lakedsp.com
I use DH with RealJukeboxPlus. You can download the plug-in by selecting product updates within the RealJukebox Plus player. Note, this works only for Jukebox, not RealPlayer.
The plug-in is good for a 30-day free trial, after that it becomes inoperational. License cost is only $10. A real bargain if you get to like DH. Best $10 I ever spent.
DH is also available as part of PoweDVD which is a software-based DVD player for PC's. PowerDVD is sometimes bundled with some new PC's, or can be purchased for about $40-$50. See Headwize Announcements for some deals currently available. There are some TRIAL versions of PowerDVD floating around on the 'Net, but from what I've heard, Dolby Headphone is disabled in these versions.
Finally, don't confuse Dolby Headphone with other Dolby products, including Dolby Digital, and previous virtualization products. You can also find more information at Dolby's website:
www.dolby.com
Try it out and post your impressions. Most people who have tried it are very impressed with it. Espescially when you turn it on and off when playing. You say to yourself, how could you listen to headphones without it. The effect is very dramatic.