The Speed Dial feature is a time saver because you can create up to 9 sites to be displayed as thumbnails whenever you create a new tab. In Opera if you click the refresh button while viewing the Speed Dial Page it will refresh the thumbnails of all the tabs so that you can see if anything has changed since the last time you visited the sites.
The Firefox Speed Dial extension has the same basic idea. You can set it to show your Speed Dial page every time you open a blank window or a blank tab.
Download: Firefox Showcase Extension
