Good article from JWT Intelligence on smart objects. These are objects that have been enhanced by the addition of computers of some kind. A good example from the article is the smart beer bottle from Heineken.
The reason I like this example is if beer bottles are becoming embedded with computer chips and sensors then it means pretty much everything will.
Another technology that will drive the rise of smart objects is Bluetooth Low Energy (Bluetooth LE). This is a low power version of Bluetooth that is being quickly adopted as way to allow smartphones and other computer devices to communicate with smart objects.
Apple is including Bluetooth LE (they call it iBeacon) in iOS7 and Google has already adopted it for Android. Paypal has already announced a hands free payment system based on Bluetooth LE and expect to see many new location-based services using this communications protocol.
Cisco is forecasting that by 2020 there will be 50 billion "things" attached to the Internet. They are also forecasting there will be 1.7 trillion things in existence by then.
Since there will likely be a lot of smart objects not attached to the Interent (like Heineken's beer bottles), I think it's safe to say there may be as many 100 billion or more smart objects in world by 2020.