If you're running OS X and use the native mail app, you know that it can be hard to integrate the GPG encryption suite. Fortunately, there's a custom solution for the Mac called GPGTools that integrates GPG with OS X and the mail app. I've been using it for several years and have been very happy with it. It's actively maintained and high quality software.
It's not hard to install and I doubt any Irreal reader would have the slightest problem. But, of course, we all have an Aunt Millie who needs a bit of extra help. Happily, Jeff Reifman over at Tuts+ has an excellent how to on installing and configuring the PGPTools suite. The process is easy and if we can get a substantial number of people to install and use it, we'll be on our way to ubiquitous encryption and a safer Internet.