Decrypting or encrypting ROT-13 text
The two methods I use:
1. Go to http://www.rot13.com/;
2. To avoid opening a new window, drag this bookmarklet to your browser's toolbar, turning it into a button: ROT-13. Then highlight text and click the button: a window will pop up with the ROT-13'ed text. Just clicking the button will give you a prompt asking you to enter text.