It seems that ubuntu has removed the sun-java6 packages from the respositories, and are now recommending the use of the openjdk-6 packages instead. To install the runtime run:
However if you need the sun-java6* packages then they can still be added by:
sudo apt-get install openjdk-6-jre
However if you need the sun-java6* packages then they can still be added by:
sudo add-apt-repository "deb http://archive.canonical.com/ lucid partner" sudo apt-get update sudo apt-get install sun-java6-jdkWhen prompted to select the licence use the 'tab' key to navigate and hit "enter"