Soulver is a funky little calculator application (Mac only) that allows you to type in plain-english statements, and Soulver will figure out the necessary equations and calculate them.
 
An example from the Soulver website:
book = $12
If I sell 100 copies of my book, how much will I make?
$1200
 
Personally, I think that everyone needs basic math skills. But I can see a market for this sort of application.
Thanks to the guys at MacResearch for this one.