Not "junk" as in "trash", but "junk" as in "tickle pickles", "flesh bananas" or "knobgoblins". You know, dicks!
To date, Japan produced at least two big ding dong peripherals: SOM was released in late 2008. It connects to player's computers via USB and even syncs to "climax scenes" in erotic games. A "piston machine" was also released for ladies.
Then there's this "tech demo" from Japanese erotic game maker Illusion Soft. The contraption has a vibration function, and it's possible to select things like size. Whether or not this contraption comes to retail is still to be decided.
Tech Arts 3D, makers of ero title 3D Custom Girl, are hard at work on this. It's, well, it's pretty obvious what it is! It is USB powered and runs on open source software for eroge.
Tech Arts is working on all sorts of sexy R&D from a mixed reality headset to implementing SOM's whack-off machine with its games. Last year, the company focused its attention on face-tracking tech. (Read: looking up skirts.)
Some people cure diseases, others solve crime. The folks at Tech Arts think about computer games and masturbation. Not necessarily in that order.
Tech Arts 3D [Official Site NSFW]