Negative voltage

Isn't it just a power supply connected backwards?

Umm, nope

It's funny that I keep telling myself I shouldn't spend ~20 bucks on stuff I don't need (GLCD), and then I find myself placing a $25 dollar order for things I DEFINITELY don't need

Well you know you need one of these:
http://cgi.ebay.co.uk/ART-USED-LCD-graphical-640x480-mono-8-4-EG9018C-/390223734243?pt=LH_DefaultDomain_212

about $12 including postage or something...