Look at the IR Jammer project page here.
The IR Jammer is a fun project that provides a bit of safe, non-destructive fun. The Infrared Remote Control Jammer allows you to render all IR remote controls inoperative! The microcontroller in this design allows for all 6 of the main IR frequencies to be targeted making this unit universal. It works by corrupting the data that is being sent by your normal remote controls.
A single press of the button sends out stream of IR pulses from the two narrow beam and two wide beam IR LEDs for 30 seconds. Each press of the button will add 30 seconds to the running timer. For remote operation you can simply connect a button to the On Sw. pads, shorting this input will turn on the IR output until the contact is opened. This would allow the device to be mounted into an old remote, brim of a hat, etc.
The compact design is the size of a 9 volt battery allowing it to be strapped directly to its power source if desired.