Yeah, there from eBay, basically they are huge single use flash bulbs. you can still buy then new from a company called Meggaflash.
I'll do a thread in the photography section about them as they are a great way to produce a huge amount of light quickly. In the meantime look at this:
Fujichrome Sensia 100, OM-2S, 21mm lens, B-setting at f/3.5, 6 Meggaflash PF330's, 1 Meggaflash PF300, tripod.
"This image was taken during our second photo expedition to the cave. I wanted to fully illuminate the Rumble Room. To do so, I knew from previous tries, would take a great deal of light. So, I used two flashguns each modified to fire three bulbs simultaneously. I chose six of the most powerful bulbs made, the Meggaflash PF330, plus one PF300 in the foreground. These bulbs gave a total output of nearly 1 million lumen seconds! This image was made possible with the collective assistance of many cavers. Tim Curtis, Mark Joop, and Lance Hopenwasser provided illumination. Chris Voudy (on rope), and Curtis Beasley also assisted. Sherpas Tony Voudy, Mark Ruocco, John Swartz, and Gary Collins helped get all the equipment down into the room!
Note the guy on the rope in the middle of the pic!
Info and pic from here: http://www.darklightimagery.net/flashbulbs.html