To install qBittorrent on Ubuntu 9.10 Karmic Koala just follow these steps:
1. Open your terminal and type this command:
$sudo add-apt-repository ppa:hydr0g3n/ppa
2. Type the following command sudo gedit /etc/apt/sources.list and add the two lines below:
deb http://ppa.launchpad.net/hydr0g3n/ppa/ubuntu Karmic main
deb-src http://ppa.launchpad.net/hydr0g3n/ppa/ubuntu Karmic main
3. Get this key by doing this:
$sudo apt-key adv --recv-keys --keyserver keyserver.ubuntu.com 47B4D1C4
4. Update your Source.list:
$sudo apt-get update
5. Then install qBittorrent:
$sudo apt-get install qbittorrent
µTorrent for USB 8GB