Google seems to be wanting to sell you more accessories this year. Today, they announced "Live Cases" on the Google Store for the Nexus 6P and Nexus 5X. These are just what you would expect from the name. They are cases that you can customize for your smartphone - of course it's limited to the Nexus 6P and Nexus 5X right now - and you can use your own picture or one from Google Maps. This makes things pretty interesting. As you could get a case that has a selfie of you right there on the back. Maybe not the best idea for everyone, but it does mean that no one else will have the same case as you. If that's something you're interested in.
So you can choose to get a map of a place on the back of your case as well. This is pretty neat, and the examples they show are of New York City - specifically showing the borough of Manhattan. They have it shown in the day and at night. It's pretty sweet and if you really love your city it's definitely worth the price. These cases from Google are going to cost you $35 each.
Another "feature" of this case is the programmable button on the back. Which appears to be using NFC - although that is not confirmed. You can program that shortcut button to open an app. Which is pretty sweet. You could program it to open the camera. So whenever you touch that button the camera opens. That might be a bit better than double tapping the power button on the device as well.
These cases are available now on the Google Play Store. While these aren't the cheapest cases out there for either the Nexus 6P or Nexus 5X, they are definitely unique. You can rest assured that no one else will have the same case as you. Unfortunately they are only for the Nexus 6P or Nexus 5X right now, perhaps they'll open it up to the Pixel C as well, since the store does still sell that AOSP device. While it doesn't sell the Nexus 6 or Nexus 9 anymore.