I bought some of these and put them in sockets in strategic places in the house. They have motion sensors and they give you enough light for you to see in the dark before they go off. In the event of a power cut and they have no electricity going in to them, they automatically come on and stay on through out the house. They can also be removed and used as a torch.
The only bug bear is when No.2 dog mooches around during the night, they keep coming on and off like strobe lighting at a rave!