The Kitronik Round 5V LED Matrix Lamp Kit offers a really bright light, which is compact and easy to mount. The unit is supplied with 9 white superflux LEDs, which collectively output around 16,000 mCd.
The unit incorporates current limit resistors, allowing it to be run from a 5 V supply or 3 x AA batteries can be used (3 new batteries will last for around 5 hours).