Shrink Tabular column space used by over 50% using a simple trick

I've recently wrapped up writing the draft of a PowerPivot book (news on that once it's published) and as part of having to make sure I "knew my onions" I spent a bit of time working my way around understanding the compression engine. I came across this post - Optimizing High Cardinality Columns in VertiPaq - by Marco Russo, and it sparked my interest in seeing how it could be applied to a couple of common data types - financial amounts and date / times. This first lead to me getting distracted building a tabular model to see how much memory columns (and other objects) used. Now i'm getting back to what took me down that path in the first place: seeing how different data type constructions affect memory usage.