Edit: Due to the fact that this article is old, the installation instructions may not work anymore. In order to successfully install the latest version of qBittorrent, please access the qbittorrent tag and open the latest article (the one on top).

The latest installation instructions for qBittorrent
Hello Linux Geeksters. As the name suggests, qBittorrent is a torrent client, similar to µTorrent, which was recently ported to the Linux systems. The latest version of qBittorrent, is qBittorrent 3.1.9, which has been released a while ago, coming mostly with bug-fixes. For more information, see the official changelog.
In this article I will show you how to install qBittorrent 3.1.9 on Ubuntu 14.04 Trusty Tahr and Linux Mint 17 Qiana.
Because it is available via PPA, installing qBittorrent 3.1.9 on Ubuntu 14.04 and Linux Mint 17 is easy. All you have to do is add the ppa to your system, update the local repository index and install the qbittorrent package. Like this:
$ sudo add-apt-repository ppa:hydr0g3n/qbittorrent-stable
$ sudo apt-get update
$ sudo apt-get install qbittorrent
Optional, to remove qbittorrent, do:
$ sudo apt-get remove qbittorrent
Or, if you want to uninstall qbittorrent , disable the recently added PPA and downgrade all the packages that got updated via the PPA, do:
$ sudo apt-get install ppa-purge
$ sudo ppa-purge ppa:hydr0g3n/qbittorrent-stable