Here's how you can install the GNOME Do application launcher in Ubuntu 13.10. You can search for items, and also specify actions to perform on your search results.
1. Open a terminal window.
2. Type in the following command then hit Enter.
sudo apt-get install gnome-do gnome-do-plugins
Do is an intelligent launcher tool that makes performing common tasks on your computer simple and efficient. Do not only allows you to search for items in your desktop environment (e.g. applications, contacts, bookmarks, files, music), it also allows you to specify actions to perform on search results (e.g. Run, Open, Email, Chat, Play, etc.) and it allows you to quickly search for many items present in your GNOME desktop environment (applications, Firefox bookmarks, files, artists and albums in Rhythmbox, Pidgin buddies, etc.).More at Noobs Lab
Additional resources for GNOME Do