This little instructable shall show you how to create a simple Infra-red jamming device which could be used for many hours of TV pranks.
Step 1: Infra-red Jammer - Parts List
For this project you shall need:
1 x 10K Potentiometer
2 x 10nF Capacitor
As many IR LED's as you please
Equal amount of 330 Ohm resistors for LED's
1 x 56 Ohm resistor
1 x 555 Timer IC
You can get most of these parts from an online retailer or electronics hardware shop relatively cheap.
Step 2: IR Jammer - PCB Layout
If you wish to create a PCB board for this circuit, I have a recommended layout here.