Simple openSCAD Top Hat

My first openSCAD model... It's now hollow! :D but I've not printed it yet.
Made following this great tutorial:
http://www.makerbot.com/blog/2011/01/28/openscad-basics-manipulating-forms/

Version 3:
-Hollow (with optional slant just incase, like me, your printer is not magical with enhanced "Prints on Air"(r) technology or you don't have a stockpile of "Super Dense Nothing"(tm) lying around the house).

Version 2:
-More tapered top
-A touch shorter