Configuring your system
Apturl.net is a web interface that install packages on Ubuntu. Since version 7.10 (Gutsy) it's possible to install packages using a protocol named apt-url. This site does the same service that Synaptic and "Add/Remove Softwares", but through a browser.
To use this system it's necessary to install the apt-url package. Download and install the apturl package or use the terminal.
Open the terminal and enter the command below:
sudo apt-get install apturl
Restart the Firefox browser.
Your system is ready.