This is Windows 2008 and i'd just like to show a "Size on Disk" column beside the "Size" column for a file (so i don't have to click on every file properties to know it).
This would be an interesting for compressed and hollow files.
You'll need a 3rd party tool that can show the compressed size easily. The powerful Explorer replacement xplorer2 can do this with a "Size on Disk" column. The old freeware tool NTFSRatio is designed for this singular purpose.
There may other options out there, but those are two I know of off the top of my head.
as per microsoft's documentation: (http://msdn.microsoft.com/en-us/library/bb776831(v=vs.85).aspx)
the ability to create custom column handlers in explorer is only supported in windows XP or earlier. the above page includes an irate user's plea for the feature's return in win8.
So the answer is, not available/not supported.