Users migrating to Ubuntu might from Windows might wonder why there is no equivalent of the "Run" entry in the default Gnome desktop menu, especially given that Linux is supposed to be so command-oriented.
The Gnome desktop actually does have an equivalent application launching window, however it is not offered in the standard menu. Instead, it is accessed by the keyboard short cut Alt + F2. Pressing this key combination will pop up the "Run Application" window, in which the user can type a command as if it were being typed on the terminal command line.
For quick tasks, this can be much faster that opening up a terminal to run a single command.