The guys that set up the "sidewalk sheds" when doing facade work (you may have seen them if you live/work in a big city) are now using fluorecent lighting (enclosed fixtures) instead of the porcelain lampholders with the yellow plastic cages. It does give much brighter light than the anemic incandecent bulbs, runs much cooler (saves on the electric bill) and last much longer.
But I suspect the biggest reason they're doing this is to prevent bulb pilferage by passers-by at night.
I don't think the fixtures they use are rated for outdoors. They look like standard indoors fluorecent lights to me (a tin box, containing two bulbs with a translucent plexiglas cover).