Anyhow, every time you install a new application (say in Gnome desktop) and if that newly installed utility comes with a file types of its own which is not presented in the OS, then it manually registers those file types thus these applications are rarely needed for the newbies But...
... assoGiate is intended for the system administrators who want to manually change the configuration of the file types in Gnome/Ubuntu (or in any GNU/Linux distribution that uses Gnome), but of course dudes (ladies included :D) like you and me also can use it to play around the system settings (yikes!) a little bit as well.
*. Search for the default file-types.
*. Edit the already consisting ones.
*. Add a New file type with Categories, related types, file names (also known as "extensions"), XML elements and other advanced options such as changing priority values, etc are also included.
*. Switch between User and System database (system database is only "shown" if you run it with administrative privileges).
*. Remove existing types (only available in the administrative mode).
*. Import/export the database... are the main features to mention.
You can install assoGiate in Ubuntu 11.04 Natty Narwhal, 10.10 and 10.04 by using the below command.
sudo apt-get install assogiateThat's it, be safe ;-).