I know there is slang already for satoshis or "mikes" etc... but I've noticed through traveling that countries use different money slang in different places for different amounts- some of them not so sensible. Relying on a world-wide slang to cope with too many zeros in digits seems difficult to do.
It's not slang, and it's not different in different countries. It's the
metric system. It already has worldwide acceptance. We just need to convince America to get with the program.
Oh wait, they already are (at least when it comes to currency). America already uses "cents" and "mills" to refer to a hundredth-part and a thousandth-part of a dollar, respectively, though the latter is seldom used these days for obvious reasons. What's the problem, again?