Home Use Program (HUP) is a program MS has with some companies that provides copies to the company's employees for just S&H (i.e. $19.95).
Right now they offer Office X and the "current version" Office 2004. I am checking every day to see if Office 2008 is added... I'm not sure if it is something the company has to arrange per some agreement, or whether MS should just alter the program to account for the "current version."