You saw Batman Begins, you've now seen The Dark Knight, and now go on admit it, you want one of those mega spotlights with which Commissioner Gordon summons the help of the Caped Crusader. But you don't have a gigawatt three phase power supply, all you have is a measly little 5V USB... don't despair, that's plenty to work with, and if you follow this instructable you'll be casting the most wicked bat shaped shadows all over your bedroom, living room and office walls.

It's dead easy if you have even the most basic making skills and great to try if you've never done any electronics before. Plus there's a little bit of fun hacking apart a Series A USB plug and using the guts!

You'll need

• A couple of old packaging bottle caps (shower bottle and single serving drinks bottle, or something similar)
• Some thick tin foil (take out tray, or aluminum roofing / flashing tape) although thin foil will work
• A cheap USB Laptop light (or the appropriate LED, wire, correct resistor and USB Plug
• A small piece of clear plastic sheet (OHP sheet or bit of old packaging)
• Some cardboard and or foamcore (not necessary but nice)
• Some low value loose change
• Soldering iron
• Hot Melt Glue gun
• Black and silver paint (spray or markers)
• About 1.5 to 2 hours to spare doing this project

Actually you only really need one, for the spotlight itself, although the other cap is useful for the base, the base could easily be made out of cardboard. here you can see the top that I used for the main part and the bottle it came from.

Given the shampoo only cost about 50p for 750ml, it would be worth buying a bottle just to use the cap and then keeping the shampoo as hand wash or shampoo refill.

Note the fact that the cap is translucent, this is quite important, because in the real spotlight there is quite a bit of light leakage through the cooling vents at the side of the lamp, and the translucent cap lets us mimic this effect rather nicely.

The single serving drinks sports cap is nice because the push pull closure also rotates, which means that the finished spotlight will be able to rotate, although this is not really necessary, of course unlike the real one, your USB spotlight won't need a crane to turn it round.