Cloudy for Gmail is a Google Chrome extension that allows you to add attachments for your Gmail from online cloud storage accounts. It supports Dropbox, Box, GDrive, Facebook, SkyDrive, Evernote and many other websites. The main advantage is that you do not need to leave your Gmail page.
The WOT add-on is a crowd-sourced enhancement to your browser protection
It is a browser add-on which lets you search via your favorite search engine
