The Trance Vibrator. One of the weirder game console peripherals ever released.
Some background. As an offshoot from haptics research, Nintendo decided to add a facility to their Nintendo64 console that allowed gamers to feel what the game was telling them. The gamer could purchase (as an optional accessory) a Rumble Pak. This was a small plastic pack that slotted into the bottom of the game pad. When filled with batteries, the game could activate the pack's weighted motor and impart a vibration into the hands of the user. Typically, this was used for effects such as the player being shot or jumping from a height. This idea was obviously seen as important by Sony, as they incorporated the same effect into their Dual Shock Playstation controller. Since then, every major console's pads have have some form of vibration feedback available or built in.
Cut forwards to 2001, and Sega's UGA development studio headed by Tetsuya Mizuguchi are designing the then mysterious K Project. K Project (since renamed to Rez) was a stock shooter in the vein of Panzer Dragoon, but with a seriously good techno score, and visuals inspired by the art of Kandinsky. Mizuguchi, being an enterprising chap, decided that the stock rumble of the Playstation 2 pad wasn't good enough for his labour of love, and set about finding other ways to immerse the player in his creation.
And this is where it gets a little silly.
Yes, he decided that a USB powered vibrator that could beat in time with the music would be a good idea.
OK, so although it's technically a vibrator (in that it vibrates) it's not designed specifically for the more normal purpose. What you get for your hard earned cash is a plastic block with a trailing USB cord, and a velvety pouch to put it in. The USB cord plugs into one of the spare ports on the front of the Playstation 2 (yes, it will power two at the same time) and the block slips into a comfortable pocket. Please bear in mind that UGA and Mizuguchi are not totally to blame in this endeavour, as ASCII (Agetech in the US) are the manufacturers and probably the designers of said peripheral.
So, everthing's set up. Fire up Rez. Flick through the options and start a new game. Start playing. As the music kicks in, the Trance Vibrator starts pulsing in time to the music. "Hey, this isn't too bad!" you think. You shoot a few enemies; notice that the motors in the pad are rumbling as well, although in time to your shots and not to the music. Soon though it's the end of the layer and at this point the Trance Vibrator goes crazy, building up in a crescendo of vibration that convinces you that the poor little block will shake itself apart. The thing is scarily powerful for a USB powered device. I think Mizuguchi got his wish though - after a while it stops being a vibrating block in your pocket, and starts being a facet of the overall experience.
Amazingly enough, this isn't just the one game peripheral that it so easily could have been. No, this is a three game peripheral. There's the obvious (Rez), another UGA game (Space Channel 5 Part 2), and Irem's great earthquake survival horror game Zettai Zetsumei Toshi (a.k.a. Disaster Report in the US and SOS: The Final Escape in Europe). Space Channel 5 Part 2 only uses it literally as a backing beat and as such it's less successful. Irem however made the earthquakes in their game trigger the Trance Vibrator for a very much enhanced experience. It's a shame that Agetech saw fit to remove support for it from the European and US versions of the game (aside from the rest of their butchery to the poor title). The European and US versions of Rez and Space Channel 5 Part 2 survived intact.
How do you get a Trance Vibrator? With great difficulty these days. As ever, eBay will probably be your best bet, but prices have gone up since the infamous GameGirlAdvance article (with accompanying pictures) on the benefits of the Trance Vibrator for girl gamers. Look to pay about £20 for a Trance Vibrator, or £40 for a Rez / Trance Vibrator box set. Is it worth it? If you can stomach the abuse from your friends, then most definitely.