After minutes of researching I found this one:
ThinkGeek :: Key Katcher
It costs $60. Only works with the older Keyboards to PS2. But with the current technology today, who uses PS2 anyways? Most of the newer boards today don't even have PS2. Plus this kind of attack is expensive, not even practical.
To stage this attack, you have to replace the keyboards sa imong target computer which can be really obvious and noticeable on a public area. Mismong pag-tangtang lang sa keyboard magduda na ang mga taw. They could call the cops and jail you for that.