1. Open your Opera Browser
If you don’t already have a copy of the Opera browser, you can download it for free from the Opera website. We’re going to need Opera here because it caches files while browsing in the cleanest way of all the major browsers.
2. Go to the web page with the flash video you want
This could be anywhere, even YouTube, but I suggest somewhere that has really nice high-quality videos like Vimeo. I used the video “Thin Frame of Blue“. You don’t have to watch the entire video now, but make sure that it fully loads.
3. Find the FLV file in your cache
Starting from your home folder, go to: /Library/Caches/Opera/Cache/
Opera will save this video directly in the .flv format, no proprietary browser stuff (which is nice), but you’ll need to find it. Perhaps the quickest way is to sort the folder by date. Since you just went to the page, the .flv file should be near the top. Alternatively, you could sort the files by file type and find it that way. Copy the file to your desktop (Command-Drag works well).
4. Download Save Hollywood
Save Hollywood is a freeware program that allows you to set movie files as screensavers in OS X. You can download Save Hollywood here.
To install it, just double-click the .saver file. It will open your System Preferences where you can choose to install it for only the user you are logged in as or all users.
Under the “Others” section, you should now see the Save Hollywood screensaver as an option.
5. Downlad Perian
Perian is “the Swiss Army Knife for QuickTime. You can download Perian for free here. Since Save Hollywood uses QuickTime to display the videos, and your QuickTime can now play FLV files, you are in business!
6. Add your FLV file to the playlist
With Save Hollywood selected as your active screensaver, click Options. Here, you can build a playlist of videos you wish your screensaver to play, set the volume, position, background color, and other options.
All Done! Now you know how to set any Flash Video file to be your Screensaver!
This tutorial was conceived by Richard from ShiftedFrequency. Thanks Richard!