As long as you have Adobe AIR installed you shouldn't have any problems installing twhirl. If you're running Ubuntu 32-bit then you can simply install the .bin file available from Adobe without any additional steps. If you're running Ubuntu 64-bit then follow the steps listed in the first post in this thread to install AIR. Once installed simply download the twhirl .air file and then click on the file to begin the installation. I'm currently running Kubuntu 8.10 64-bit with KDE 4.2.2 and twhirl installed flawlessly.