Windows/Mac/Linux (Firefox): The asdf-jkl Firefox extension adds tooltips to the fox's chrome that display keyboard shortcuts associated with the item your mouse pointer is hovering over. For example, the address bar shortcut is Cmd+L, as pictured. (It's Ctrl+L for Windows peeps, so the tooltips are platform-aware, too.) Also asdf-jkl adds a Keyboard shortcuts item on Firefox's View menu for quick