Here's a nice video about NFC (near field communication). The latest Android phones, equipped with NFC, allow people to pay for purchases using credit card details loaded onto their phone. As the video shows, you can tap the point of sale terminal with your phone and have small purchases deducted from your account. http://googleblog.blogspot.com/2011/10/more-google-wallet-merchants-are-live.html
The second cool thing about NFC is its ability to share content using 'Android Beam'. It works a bit like bluetooth, and allows users near each other to share just about anything: videos, website links, contact details, images etc. Just tap and go.
The other cool thing about the latest Google phone? You can unlock it by smiling at it. :-)