Screencast software lets you record what you do on the computer visually so you can play it back later. It can be used for making tutorials and other instructional material, either for yourself, or someone else (your family, a class, etc).
TechSmith, the makers of SnagIt (the screen capture utility) have a special on their site for “PC Plus Magazine readers from the United Kingdom” where you can download the older version of Camtasia (their screencast software) and then get a free registration code. I’m not sure when the special ends, so definitely check it out soon! I heard about this on RedFlagDeals.com and they have the appropriate links to follow.