To show your Joomla website to others in forums, on twitter, etc., it is useful to make a screen shot of the site. The problem is that if you use "Print Screen" or the "Snipping Tool" that comes with Windows Vista, you only copy what you see on the screen, not the entire website.
Using a Firefox plugin called "Fireshot", you can easily create a print screen of the entire website. Fireshot also gives you editing and annotation tools and you can save a screen shot in PNG (preferred), GIF, JPEG and BMP.
Below you see two examples of a screen shot of a Joomla website, one with the Snipping Tool and one with the Fireshot plugin.
A screen shot using Snipping Tool - you can only capture what you see on the screen
A screen shot capturing the entire website using Fireshot
The Fireshot plugin is available in the extensions repository of Firefox.