When you post to groups such as Flickr, or to blogs using tools such as Movable Type, you are often free to use a selection of HTML tags. This is very handy for adding links, images and basic formatting, but it comes with a downside—if you ever want to write an HTML snippet that someone can read, perhaps in order to allow them to cut and paste it, you have to manually escape the different HTML entities. < becomes <, > becomes >, & becomes & and " becomes "

To make life easier, I've written a Greasemonkey script that attaches itself to any <textarea> elements on the page and provides a handy icon that when clicked on converts any special characters into their corresponding entities.

Click here to read more and install the script.