Whether you’re a creative professional or you just need access to data, like images or documents, when you’re not at your computer, how to get it from here to there has evolved from the portable USB drive to the ubiquitous “thumb” or flash drive to solutions that don’t involve hardware that can be lost, broken or stolen.
Double-clicking a file usually opens the file in an assigned application. We may not always want to use Picture Preview or QuickTime to open an image file, for instance, or to open picture files with Preview, and it can be quite annoying to have the “wrong” application open every time. Of course, we shouldn’t blame the stupid computer for keeping us from our fav pics and tunes because it’s, well, stupid and just doing what we tell it to, after all. Since we tell it what to do, we change tell it to do something else when we double-click a given file type.