If you have installed Twhirl, you might want it to start automatically when you log in to your computer. This can be easily done. Go to Sytems -> Preferences, and click on Sessions.
When the Session Preferences dialog opens, select the Startup Programs tab and click the Add button. Then enter “Twhirl” (or any name you want) as a name and enter the following line to the command field (see pic below):
Click Add, and close Session Preferences.
To test if this works, you can log out and then back in. Twhirl will start automatically once you log in.