TiVoTool allows you to download, Stream, or Burn videos from your Series 1 or 2 TiVo or DTiVo. It is a front-end tool (perl script) and GUI ( for OS X 10.4) to pull MPEG2 files (.ty unscrambled) off of TiVo (via vserver hack) for playing in QuickTime 7 with the MPEG2 plug-in.
You need vserver running on your TiVo for TiVoTool to work. vserver can be found here.