After a quick walk around a hardware megastore you can find some inexpensive plastic torches or lanterns, designed to run from large 6V batteries or combinations of C or D cells. These are perfect for hacking, just as Instructables user "kevin1ab" has demonstrated. With his version, the bulb has been replaced with a few RGB LEDs, which are controlled by an Arduino. To make the lantern more interesting, he's not only fitted three potentiometers to allow individual control of the red, green and blue elements - these levels are also displayed on a typical LCD module added to the battery area as shown below:d
Although it might seem simple, the results are a pretty cool thing. So visit the Instructable for complete details to make your own. And for more, we're on twitter and Google+, so follow us for news and product updates as well.
If you're looking to make more creative designs with LEDs, consider the Freetronics RGBLED: full colour module. It includes a bright RGB LED on the top of the board and a WS2801 constant-current, addressable, multi-channel LED driver on the back. This smart module can be daisy-chained, so you can connect a number of these together in a string and drive each of the module colours individually from your microcontroller. For more information and to order, visit the product page.