These Schemes might be Mac only. If they are, let me know and I will add some PC ones too.

Punko
Rave
Collidescope
B 52
Baseball
Bleen
Clock Work
Copperplate
Drew Berry
Grey Mist
Hi-Res
Ice
Mac In Black
MacAddict98
Mac OS 3D
Mac OS X
Nuts 'n Bolts
OS X-Tech
One of my personal favorites, Purple Tech2
Rhapsody
Scherzo
Apple
Copland Hi Tech
Gizmo
Hackers
X-Rated
BeBox