Ctrl + Alt + T was not working as a shortcut for terminal in my fedora 17, I was used to gnome so here is the way to assign a shortcut for terminal in fedora.
Enter name as Terminal and command as gnome-terminal.
Search for "shortcuts" in your launcher you should find the keyboard settings application.
Now click on the add new shortcut button.
Now the command is created to assign a shortcut double click the created shortcut in custom shortcut, you can now press the desired shortcut keys to assign it to terminal
You can assign any number of shortcuts in this manner.