Check Debra Dalgleish's website:
http://www.contextures.com/xlfaqApp.html#Unused

--
Regards,

Tushar Mehta
www.tushar-mehta.com
Excel, PowerPoint, and VBA add-ins, tutorials
Custom MS Office productivity solutions

In article ,
says...
I used a macro to import data into a new worksheet. there isn't a great deal
of info the spreadsheet (probably about 29KB) but the worksheet has a size in
excess of 29MB. It seems to be filled with blank cells (no formulae) as the
scroll bar on the right is tiny and if you drag it to the bottom the row
number shows 60-odd thousand. How can I reduce this file so it just saves the
cells with data? The worksheet itself does not have a macro within it.