1)   Klingon Screen Saver 1.0
Klingon Screen Saver is a Freeware Mac OS X screen saver featuring a 360 degree rotating logo of the Klingon Empire 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 logo of the United Federation of Planets 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 logo of a StarFleet Medical Facility.