Screen recordings can be a great teaching tool, especially for visual learners. If you've never seen one before, check out jot.com's collection of wiki editing tutorials. You may notice they are created with Camtasia Studio, which is an excellent screen recording authoring package. Unfortunately at $299 it's out of the reach of some budgets. If you're interested in screen recording but can't afford Camtasia Studio, or if you'd prefer to experiment before committing, check out Camstudio or Wink. Each has its virtues. Camstudio is Windows-only and is more versatile in terms of output formats--it can record out to a variety of video formats or to a Flash .swf file. Camstudio lacks some of the presentation markup tools (for composing things like text overlays, animations and so on) that Wink has. Wink runs on both Windows and Linux but is limited to .swf, standalone .EXE or HTML files for output. Either is capable of producing useful screen recordings -- the one you should choose to try out probably depends on your computing environment. If you have Flash, Wink is probably easier if you're just getting started with this kind of resource, but both are worth a look (as is Camtasia Studio) if you have a real need to produce this kind of material regularly.