Too Cheap to Buy a PS3 Dualshock Controller?

This strange appendage snaps on to the bottom of your standard PlayStation 3 SIXAXIS joystick, turning it into a poor-man’s DualShock controller.
PEGA’s oddly-named “Vibrating Bag” adds rumble capability to your stock PS3 controller. Now they don’t specify if the vibration actually works when the game generates its feedback signal, or if the thing just continuously rumbles.