directory sizes

[Matt Marnell]

In my never-ending quest to find the perfect partition sizes for my new 30 
GB box, I'd like to perform an audit of the users of this list.  If you 
don't mind, please submit the total space located in each of these 
directories...thanks.

/ (root)
/var
/usr
/tmp
/home
/opt
*for the root value, please don't count the space located in the other 
directories on the list...I just want the size of root plus all other files 
and dirs NOT in the other dirs on this list....THANKS VERY MUCH!!!

Matt