1, To optimize the comparing of the length of vector:
SimpleVector.length()^2; SimpleVector.distance()^2
2, For animation、camera moving 、physic simulation and so on:
Interpolation - linear、sin、pow、slerp and so on.
3, For animation、rotation Interpolation:
Quaternion
I could...but to be honest, this would be very low on my priority list. If you already have some stuff that does this, i would be happy to include it though.