UPDATE, January 5th: low-energy, coiled light bulbs (we use them in our house) contain a tiny bit of mercury, so take care that you don’t drop them. Be careful when disposing of these bulbs (they’re supposed to last five years, so I haven’t done that yet). I saw the news on the BBC site, and if I can retrieve the article, I shall post a link to it here.
UPDATE, January 6th 2010: Several of our low-wattage, coiled light-bulbs burnt out after only three years, and that was with very little use. What a disappointment!