I recreated the old After Dark "Flying Toasters" screensaver for my mac. The program I used can wrap a SWF in a .saver format that a mac can read. That being said, it's not optimized and will likely kill your battery.
Oh well! Nostalgia is worth it!
To install, because I'm not a "verified developer", it's a little tricky. You'll have to move the .saver file into "~/Library/Screen Savers/" and then you'll be able to access it from your screen saver selector.
I guess you can go grab it here: Dropbox Link