I had this link
emailed to me this morning from a budding converter in Russia. He's just playing around with LED's at the moment but created these low power indicators.
He used 24 red LEDs (8 candell each) and 100 ohms resistors per 4 LEDs. A regular bulb is disassembled and the leds are connected to the metal part of the open bulb.
The page is in Russian but the pictures are self explanatory. I might just do this myself in the future.