Transmission 2.42 is released. Transmission is installed by default on Ubuntu 11.10. The installed version is 2.33 and to upgrade to the latest version you can use the transmissionbt PPA for the latest stable build of Transmission.
To add the PPA and upgrade Transmission open a terminal window (press Ctrl+Alt+T) and copy+paste the follwoing lines:
sudo add-apt-repository ppa:transmissionbt/ppa
sudo apt-get update
sudo apt-get upgrade