The Twine sensor is one of the more successful Kickstarter projects completed. It is a battery-powered wifi sensor node. It has internal temperature and orientation sensors and can use other sensors purchased separately.
It looks like they have fulfilled Kickstarter orders as they are now available for purchase from the designers website Supermechanical and from Amazon.com. They are more expensive than the $99 preorder price: $125 from Supermechanical, $140 from Amazon.
My opinion: this could be the basis for a household Internet of Things but the price point has to come down, probably by half at least. Thoughts?