Adhoc Party extends the reach of PSP games with local wireless play like Dissidia: Final Fantasy by giving them Internet play via a PlayStation 3 connected to the PlayStation Network. Sony has been beta testing the service in Japan without announcing it for any other region. You can digitally import Adhoc Party by downloading it from Japan's PlayStation Store, but wouldn't it be nice if an English version came out?
Sony might be preparing one since they just trademarked Adhoc Party for everything from "automatic operation transmitting of digital data in the nature of video game software" to "amusement parks". Since the service made its debut over a year ago this doesn't seem like a protective trademark.
Monster Hunter Freedom Unite recently came out in North America and it's a prime candidate to take advantage of Adhoc Party. Perhaps, Sony is planning a domestic release soon?