When you install Chromium on Ubuntu 11.04 using the software center you get the stable version on your machine. However, if you want to flirt around with the latest features you will need the Dev channels to be able to use the developer version of Chromium. Let's see how to update the channels to dev version to install the latest developer version of Ubuntu 11.04.
Adding the dev channels repository to your Ubuntu Repos:
sudo apt-add-repository ppa:chromium-daily/dev
sudo apt-get update
Once you have added you can start your update manager to update chromium (currently 12).