[nine_k]

This probably should not completely replace street lamps, but could help better light some areas that are naturally dark and shady. Trees, instead of concealing the streetlights, would give off some light.

Consider evergreen grasses that could probably be made to glow, too. Such grass could nicely light up park lanes at night. Slightly glowing evergreen bushes growing along a walkway could help one walk at night.

Also, consider how helpful such a natural illumination would be during a power outage, especially when it happens due to a natural disaster. The light might be faint, but it will help people orient themselves, help rescue helicopters recognize the terrain, etc.