Reducing the size of PowerPoints: PPTX PPT10 / 12 / 2010
This is a follow-up post to another one where I give a few tips on how to make PPTs smaller. It dealt specifically with how saving a PPTX to a PPT seemed to double the file size.
I discovered another reason why the file size can be so large in a PowerPoint. If you drag and drop pictures into the PPT, it seems to junk it up and never be able to compress the images down at all. To fix this, always use the "Insert Picture" menu item to browse to whatever image you need and then put it in the PowerPoint. You can delete all the pictures and then re-insert them by using the menu items.
By using the Insert Picture command, I was able to shrink a PowerPoint down from 15MB down to 3.3MB