On clicking Gmail's "Compose" button, a window appears in the right corner of the screen. Well, this window has new options now. In the top-right corner of that "Compose" window, you will find three icons: Minimize, Full-screen and Close. By clicking the one in middle, window gets enlarged.
These tools let you store and share your bookmarks online. Once you've configured your account and customized your browser it becomes easy to bookmark, describe and tag your Internet discoveries. Just click the toolbar icon and you will be prompted to save your bookmarks (including comments and tags) to the online service you have chosen.