As someone who frequently wakes up in the middle of the night, and fumbles around the dark while trying not to wake my wife, I find these brilliant:
It's such a simple idea. Called ConnectLights, they don't need to be wired in, just placed over the outlets and screwed on. Two prongs inside the ConnectLights tap the juice from the outlets. Up front is a motion detector and an LED light, and you can choose whether to "network" them to nearby ConnectLights or have them act as standalones. And the benefit of these over plug-in nightlights is that they leave the outlet free.
ConnectLights are currently killing it on Kickstarter. The campaign's only been live for a few hours, and at press time they'd landed $95,706 in pledges on a $30,000 goal, with 29 days left to pledge.