Microsoft Office Labs recently launched a new service called Community Clips allowing users to create and share 'how-to' videos about Microsoft Office. The cool thing is as part of the service they have created a free screencasting tool that is very easy to use. All you do is install it, click record and it will record the output from your screen along with an audio track from any installed mic. Once your done recording just click stop and you can view your video, save it or upload it directly to Soapbox.
It also supports screencap from individual windows or user defined areas of the screen.