They ARE cheats:) The reason for them being called cheats is because the eye cannot register so many moving frames at a time. Therefor we can get away with blurs or sometimes no inbetweens to suggest a certain movement.
Hold your hand out in front you and look at the back of it. now wave it back and forth...
You have your start pose and your end pose.... You can cheat the inbetween by just adding a blured hand in the middle.
Or you can draw a hand in the middle with 10 fingers.... Although this seems odd, it is actually what you see because your eyes are not registering the movement fast enough.
So as you can see cheat and get away with the inbetween with just a blured hand. (motion blured).
The best way to do this is to understand your movement... Add the inbetween with 10 fingers... and then blur that frame... This is what you naturally see....
CHEATing is used a lot in animation. Often times you will see a walk from the waste up, or a lot of camera work to hide the animation. This is a way to FAKE or CHEAT movements.
It is a way to cover up poor animation or a more time efficent process. However you can get your point across, do it. Cheating of faking movements, but my advice is to learn how it should be done first to get a basic understanding of the movement. THe best animation book out there is the Richard Williams -Animator's Survival Kit. So many 3D films feel stiff because they lack the understanding principles of animation and just move models around.
A good example of this is Pixar. They have amazing animations because everyone is or has some knowledge of tradtional training. Go to their web site and look at their current job listings... They have an animation position for 3D open right now. The only requirment is.... "Must have tradtional training"
If your not one to read and don't want to invest in the Richard Willams book then you can find many of these techinques where they fake movements on youtube. Pretty much every anime film fakes movements with croping or effects. I think the best one's though are the films that not only fake movements but also show scenes where they pull back the camera and show that they know how the movement is done.
Knowing how the movement is made will help not only fake movements when you need to, but also open you up to longer camera shots and scenes that take place in a single enviorment with not many cuts.
Best of luck to you, and I do advise getting the Animator's Survial Kit.
apscalmato
http://apscalmato.com/animations/
http://WhenTheWorldGoesDark.com