SnapPower GuideLight Outlet Cover Plate with LED night light - $5 @ Amazon $4.99
This is a standard duplex power outlet cover plate that has integrated LED night lights. Great for a dark hallway or garage. No batteries are required, and the lights are powered off when ambient light is sufficient.
Woot had a competing brand in a 5 pack for $40 ($8 each) the other day. This is now $4.99. Shipping is from Japan, so will take 2-3 weeks.