I just changed allthe outside lights for energy efficieny bulbs. I had them spare because I cant be bothered with waiting for them to work indoors when I want light. I had one in our room, but to see in the wardrobe involed panning to turn them on 30 seconds before you needed them.
Even WORSE outside. It's cold, and they just aren't glowing properly. You'd need to turn them on 10 minutes before you need them!
This technology has a way to go yet I think!