What is all this captcha nonsense?

Captcha is an acronym that stands for Completely Automated Public Turing test to tell Computers and Humans Apart. In English this basically means that I'm trying to ascertain whether or not you are a real person or a spam-bot. Because some forms on the site (such as comments) are open to anyone using the site they provide a way for open discussion amongst all user of the Internet. Unfortunately 'All users of the Internet' also includes the rather annoying set of spam bots. These are infected PCs that tirelessly trawl the web looking for comment forms such as mine and then submit spam messages to them. The captacha scuppers these little sods and prevents them posting endless drivel onto the site.

If you are logged in to the site you should never see a captcha but all the while are are logged out (or you dont have an account) you will have to enter the captcha when submitting public forms such as the Leave a Comment form. You will be presented with a randomly generated sequence of letters and numbers, all you have to do is type them into the box provided. Thats it!