After buying one of the new Intel-based Mac Laptops I was horrified to find out that my favorite screen saver is only available as a PowerPC binary, which, it appears, can't be used a screen saver. I've loved the space travel screen saver ever since I first saw it on the original NeXT cube, and I've tried to keep it on every machine I've used since.
I was almost ready to resign myself to doing without my beloved screen saver when I discovered that you could write screen savers in Quartz Composer, a really cool visual programming environment for Mac OS X. After only about an hour of fiddling I had a reasonable prototype working, and with a few more hours of experimentation I had this, which does a pretty good job of duplicating the classic Star Trek view screen effect.
This 'program' should work on any Macintosh running Mac OS 10.4 or later, either PowerPC or Intel based.