Screenlets is widget applications written in Python, by default comes with many widgets such as ” system monitory, RSS reader, sensors indicators, clocks, calender, … etc”, you can install additional screenlets.
Screenlets 0.1.4 comes with many improvements and many bug fixes specially for Ubuntu 11.04 Natty Narwhal with Unity Interface, otherwise the Screenlets 0.1.3 wasn’t working quite good in Ubuntu 11.04 Natty Narwhal Here.
Install Screenlets 0.1.4 In Ubuntu 11.04 Natty Narwhal | PPA
sudo apt-add-repository ppa:screenlets/ppa/ubuntu
sudo apt-get update
sudo apt-get install screenlets
PPA works in Ubuntu 10.10 Maverick, Ubuntu 10.04 Lucid, and Ubuntu 9.10 Karmic as well.
Install additional Screenlets Here.