I have discovered a very handy Firefox Extension the other day…its called Better Gmail.
The extension has many interesting features like changing the skin of Gmail interface, keyboard macros, saved searches etc…but the ones that I like most was the secure access and attachment icons. The secure access forces the Gmail to use https instead of http, and the attachment icons just display an icon of whatever attachment you have in your emails. Here is a brief description of the extension:
A comprehensive suite of Gmail enhancements, including skins, saved searches, keyboard macros, secure access, attachment icons, attachment reminders, label colors, signature floating and more.