Graphical user interfaces help command discovery, while command-line interfaces help command efficiency. This article tries to explain why. I reached it when reading the list of references from the introduction to Ubiquity, which is the best extension to firefox I have seen so far. I expect to start writing Ubiquity commands soon, since I have already been using extensively the 'keyword shorcut' functionnality of firefox's bookmarks and we have already done work in the area of 'language interaction', as they call it at Mozilla Labs, when working with Narval. Our Logilab Simple Desktop project, aka simpled, also goes in the same direction since it tries to unify different applications into a coherent work environment by defining basic commands and shorcuts that can be applied everywhere and accessing the rest of the functionnalities via a command-line interface.