Devised by OpenDNS, DNSCrypt is a technology which encrypts traffic between your computer and supported DNS servers. This makes it more difficult for others to snoop on your activities, spoof DNS services or use various man-in-the-middle attacks.
Simple DNSCrypt is an open-source front end which allows viewing and configuring the system with the absolute minimum of hassle.
On launch the program displays your installed network adapters and default DNS resolver details.
At a minimum, all you have to do is click the adapters where you'd like to use DNSCrypt, and click "Primary DNSCrypt Service" to turn the service on.
As a quick check, we ran NirSoft's DNSQuerySniffer on the same adapter: it picked up traffic at first, but stopped as soon as Simple DNSCrypt was enabled.
If you'd like to tune the service further there are lots of extras to explore, including an option to use your computer as a resolver for other devices (smartphones etc).