1)   Klingon Screen Saver 1.0
Klingon Screen Saver is a Freeware Mac OS X screen saver featuring a 360 degree rotating Klingon Empire logo from Star Trek.

 2)   Federation Screen Saver 1.1
Federation Screen Saver is a Freeware Mac OS X screen saver featuring a 360 degree rotating United Federation of Planets logo from Star Trek The Next Generation and Star Trek Deep Space Nine.

 3)   StarFleet Medical Screen Saver 1.0
StarFleet Medical Facility Screen Saver is a Freeware Mac OS X screen saver featuring a 360 degree rotating StarFleet Medical logo from Star Trek.