My workspace has really become overwhelmed with bits of papercraft projects, complete and incomplete. In an attempt to take control back from the chaos of my hobby, I invested a little money in what appears to be the perfect organizational tool:
A photo album! The sticky pages are great for holding the standees in place, and everything stays visible so it's possible to actually find something!
Now, I admit I've only had the standees organized in the book for a couple hours, but this does seem to be the most ideal solution possible for organizing standees. I'm now motivated to get more cut... I have hundreds more already printed!