Biolite Eon and friends
Nice looking, and apparently better for you (than the more usual desk lamps), the Biolite apparently more closely emulates the natural light of the sun to reduce the wear and tear on the human biosystem caused by artificial light. It would be interesting to read some of the research behind this, but whether it works as claimed or not, it's still a really nice looking desk lamp.
For those of us who prefer a more ambient light to work by, have a look at the ToFU: