I have recently installed Ubuntu 9.04 Jaunty on my machine. Let me introduces Ubuntu to people who don’t know about it.
It is a Open source OS from Canonical, which can be downloaded free from web. It is available as both server and desktop editions.

After installing Ubuntu I have had to install day to day applications which I used everyday. One of them is tweetdeck which is a Twitter client. For Installing Tweetdeck on Ubuntu (Linux) machine, there has to be a correct install for Adobe Air suite on your machine.

These are the following steps that should be followed:

1. Go to http://get.adobe.com/air and download latest version of the Adobe Air (Adobe AIR 1.5.2 Installer).
2. After downloading AdobeAIRInstaller.bin on your computer. Right click the file and got to Properties, then got to Permissions and check the box stating Allow Executing File as Program. (Properties>>Permissions). This will make sure the when the file is double clicked it is executed right.
3. Copy the file AdobeAIRInstaller.bin in home folder in ubuntu.
4. Now open terminal and run the command chmod +x AdobeAIRInstaller.bin
5. Now run sudo ./AdobeAIRInstaller.bin on terminal. This will install Abobe Air on your Linux Machine, in this case Ubuntu
6. Now download and install the latest version of Tweetdeck from http://tweetdeck.com/beta/download/ which is currently 0.30.5.
7. You are done with Tweetdeck on Linux (Ubuntu) now. Happy Tweeting.

Update: I faced a problem after installing Tweetdeck, the columns are not populated automatically the first time. The solution to this problem is not Uninstalling and then Reinstalling. But the Solutions is to go into settings and update your correct Twitter login Details there and then Restarting Ubuntu and Tweetdeck, this is how I solved this problem.

If you are still facing any problems then you can ask them via Comments.