On the Internet you will come across commercial and free options; both produce the same end product.  The freeware collection of useful tools is less crowded.  MP3 Skype Recorder and Skype Call Recorder are freeware options that record audio directly from Skype to a digital file.  A problem with the aforementioned options is that they create lossy audio (i.e., MP3), which is a lower quality format to lossless formats (i.e., WAV or AIFF).

The alternative free option is to manipulate your sound card with Audacity.  On newer PC's this is easy when you know the hidden trick to enabling the sound card configuration.

Thus Skype combined with Audacity + Levelator = podcast

While the above solutions will capture audio, they do not capture video.  For full audio / video recording I have found the best options are Total Recorder VideoPro Edition or Pamela.  I have used Pamela for Skype only recording, and Total Recorder for the all-in-one solution.  The weakness in Total Recorder is that its a technical solution requiring a savy computer user, whereas Pamela is focused on basic computer users of Skype.

If you are only looking for an audio capture solution, then Audacity is the open-source choice.