FLV files cannot be edited without converting them first. The best way to do this is with SUPER: http://www.erightsoft.com/SUPER.html (free download)

Convert to a suitable format (wmv for Windows Movie Maker, mov for iMovie, either will work for higher-end editing programs).

Windows Movie Maker is free on any PC, and iMovie is free on any Mac, so all of us already have the tools to edit videos.

The best way to download videos as of November 2008 is RealPlayer (free at real.com). Once installed, it creates a download link right above the video you want to download. If you are on a public computer and cannot install software, try using zamzar.com, a service that will e-mail you the downloaded file.