Unity Bookmarks Lens displays your bookmarks in Dash so you can easily search all your bookmarks with a click.
sudo add-apt-repository ppa:nilarimogard/webupd8
sudo apt-get update
sudo apt-get install bookmarks-lens
For Ubuntu 12.04, use the commands below:
sudo add-apt-repository ppa:ted/bookmarks-lens
sudo apt-get update
sudo apt-get install bookmarks-lens
Once installed, run the following command:
setsid unity
And the new Unity Bookmarks Lens should show up in Dash. If the new lens doesn't display any bookmarks, try restarting your computer.