In response to today's XKCD, we, as a group, definitely need to come up with new mnemonics for anything and everything.

For reference, here are his:

Order of Operations:
Please Email My Dad A Shark
People Expect More Drugs And Sex

SI prefixes (high):
Karl Mark Gave The Proletariat Seven Zeppelins (, Yo)

SI prefixes (low):
Microsoft Made No Profit From Anyone's Zunes (, Yo)

Taxonomy:
Katy Perry Claims Orgasms Feel Good Sometimes
Kernel Panics Crash Our Family Game System

Geologic Periods:
PolyCystic Ovarian Syndrome Does Cause Problems That Judicious Contraceptives Partially Negate

Resistor Color Codes:
"Big Brother Reptilian Overlords," Yelled Glenn, "Brainwashing Via Ground Water!"
Be Bold, Respect Others; You'll Gradually Become Versatile, Young Wikipedians!

Planets:
Mary's "Virgin" Explanation Made Joseph Suspect Upstairs Neighbor

Great Lakes:
Sailor Moon's Head Exploded Once
Some Men Have Explosive Orgasms