Gmail Compactor is a Greasemonkey script for Firefox which will allow us to reduce the size of the folder list in the Google Mail, located at the left side of the messages,So you can ‘convert’ your Gmail links (Inbox, contacts, sent, etc…) to icons. So we can get enough vertical space, which will be very useful to add other gadgets or to expand other features, such as chat contacts.
Not just the icons can save space, but this script also removes the Gmail logo and the search bar located within the area of the folder list, which also wins a lot of space on the right side, where we have located mail messages.
In order to install Gmail compactor on firefox you must have Greasemonkey installed,if you don’t have Greasemonkey script addon installed on Firefox,then download it (click)here
Link: Gmail Compactor