I still need sun’s java plugin to access my internet bank. The recent Ubuntu 10.04 (Lucid Lynx) have removed sun packages from the official repository. But you can still quite easily install Sun java plugin by :
sudo add-apt-repository "deb http://archive.canonical.com/ lucid partner" sudo apt-get update sudo apt-get install sun-java6-plugin
source: beeznest.wordpress.com