This is a cool way to much more easily search your emails for those extra large files taking up way too much space! New today from Google:
Search emails by size more easily
Released on 2/25/2014
The Gmail advanced search box now has an option to search emails by size. Emails can now be searched without using operators like “size:” and “larger:”. The advanced search options can be accessed by clicking on the down arrow in the search box in Gmail.