Lighting is an important part of setting your home office up with proper ergonomicw in mind. Poor lighting can cause eye strain, glare, headaches, and other related maladies. It can also be an instigator for Seasonal Affective Disorder (SAD).
If you're looking for a cool but functional computer light, the ThinkGeek Computing section offers the Eclipse Computer Light, specifically made for eliminating glare on the monitor.
And here's a blog run by a friend that is entirely devoted to SAD, lighting, and the science behind it all.