Step 1: I need to start somewhere.
50mm PVC Pipe
50mm Threaded PVC Fitting x 2
Threaded PVC end cap Fitting
Smallish Toggle Switch
12V 24LED Downlight Bulb (They are available in different colours)
12V rechargeable battery
Small piece of foam
Tape, Cable ties and heat shrink
A 9V battery will also work but the the light won' t be that light or battery holder may also work if you can get it to fit and it has enough power example 8 1.5V AA batteries.
Diagonal pliers (I had to look this one up, I know them as a Side Cutter - http://en.wikipedia.org/wiki/Diagonal_pliers)