There are a number of ways that natural light can be incorporated into a room. Skylights, for example, are a very effective way to obtain a maximum amount of light in an area that cannot fit a traditional window. If you are thinking about installing them in your home just make sure they are double-paned and that the flashing is done correctly.
Another effective way to add natural light is with clerestory windows. Placed high on a wall, these short but wide windows allow a lot of light to enter a room but, due to the roof overhang, do not permit too much heat from the sun to come in during the summer months.
Light tubes are another natural lighting method to consider. The tubes are coated with highly reflective material that helps to channel sunlight. They are also fitted with a lens that amplifies low-level light but lowers the sun's intensity at midday. As daylight floods the interior space through these light tubes a diffuser distributes the light evenly.
If you are having a house built or thinking of renovating your existing home, why not think about using some of these methods to naturally light up darker spaces?