How the heck do those penguins jump off and land from (very!) high places without shattering every bone in their body...?!

Because Tom McGrath made them that awesome.

Umm... they're cartoons?

Like jackandjill said, they're cartoons. They don't have to follow our rules of physics o whatever it is.

Like them 2 said, they're cartoons.

They are probably very squishy. And also they must be veeeery light. XD

Ah yes... the magic of animation! :D

Its only to give the character's action's some emphasis, and to make it look as if they are amazing spy penguins that are superiously strong and can jump off 20 foot buildings. (and of COURSE they can! XD)
They do the same animación thing with Kowalski's abacus o clipboard; he pulls it out from behind his back somewhere, but nobody knows how.

One word: 'Agility'
These Penguins are not normal Penguins. They are strong, brave, can talk and are super agile. They are able to jump onto and off of very high places, without serious injury, because of this advantage.

I highly doubt Skipper would let his team do something like that, if they didn't have the skills and agility. Skipper knows what his team is capable of and he never pushes the limits of their skills.

Because there is más to these penguins than meets the eye... o_o

One word.... AWESOMENESS!!! They're not your average penguins their más then that...their FREAKING AWESOME CARTOON PENGUINS!! They can do what most men can't!! They, are da bomb diggity!!!

Secret military techniques. All I can say.