Cutscene Ceiling Clip

Cutscene Ceiling Clips or Cutscene Clips abuse of the process that freezes Crash on the ground at the beginning of cutscenes to clip him through/inside ceilings. Cutscenes can still teleport Crash after clipping so it's only useful with cutscenes that don't teleport Crash.

History
Komodo522 discovered the glitch in 2009.

Twinsanity Island's blue gem (100%)
It's possible to clip through the platform of the blue gem puzzle, removing the need to wait for the rotating platform.

Classroom Chaos (100% and All Levels)
You can clip at each hall monitor section.

Cavern Catastrophe (100% and All Levels)
A cutscene clip is possible at the end of the level, but it's 3 seconds slower.