Seen people missing an autorun key, and I'd just like to share my "workaround". It only works with the Steam Overlay, so be sure to have that activated. Its pretty simple, all you have to do is press W, Shift and TAB at the same time (be sure to stand still when you do this, otherwise it wont work), then press shift + TAB again to remove the Steam Overlay and voila, you'll run without having to hold in your W key or jimmy something inbetween your keys.